Search for "furfural" in Full Text gives 38 result(s) in Beilstein Journal of Organic Chemistry.
Beilstein J. Org. Chem. 2025, 21, 2618–2636, doi:10.3762/bjoc.21.203
Graphical Abstract
Figure 1: Structure of thiazolidinone derivatives.
Figure 2: Selected examples of commercial drugs containing the thiazolidinone core.
Scheme 1: Multicomponent reaction of benzaldehyde, rhodanine, and piperidine in ethanol leading directly to a...
Scheme 2: Substrate scope of the EDA-catalyzed Knoevenagel condensation reactions using a range of aromatic/h...
Scheme 3: Limitations of the EDA-catalyzed Knoevenagel reactions for the synthesis of rhodanine or thiazolidi...
Scheme 4: Plausible reaction mechanism for the EDA-catalyzed Knoevenagel condensation reactions.
Scheme 5: Substrate scope of the HPW-catalyzed GBB reactions.
Scheme 6: Synthesis of imidazo[1,2-a]pyridine-thiazolidinone hybrids by EDA-catalyzed Knoevenagel condensatio...
Figure 3: Overlay of predicted (red) and experimental (black) NMR spectra for compound 3n: a) 1H NMR spectra ...
Figure 4: a) Molecular structure of 3n with crystallographic labeling (50% probability displacement). b) Pers...
Scheme 7: a) Tautomeric forms of thiazolidinones and b) resonance structures for compounds 3n and 4n.
Figure 5: Molecular energy as a function of the torsion angle obtained from a relaxed dihedral scan at the M0...
Figure 6: Identification of the carbon atoms used in the theoretical study of chemical shifts. In red, easily...
Figure 7: a) Visual impressions of the solvatochromic study in various solvents (10−5 M) after excitation wit...
Scheme 8: Proposed ICT-type mechanism for the fluorescence process, adapted from ref. [89].
Figure 8: Photophysical study in aqueous solution under different pH values for compound 3n (10−5 M) at room ...
Scheme 9: Two equilibria of compound 3n in aqueous solutions, adapted from ref. [92,93].
Figure 9: Molecular fragments associated with intramolecular charge transfer states.
Figure 10: Frontier molecular orbitals of compounds 3n and 4n in three different states: protonated, deprotona...
Beilstein J. Org. Chem. 2025, 21, 2103–2172, doi:10.3762/bjoc.21.165
Graphical Abstract
Figure 1: C2–C6 biobased carbonyl building blocks.
Scheme 1: Proposed (2 + 2) route to glycolaldehyde and glycolic acid from erythritol by Cu/AC catalyst (AC = ...
Scheme 2: Reductive amination of GCA.
Scheme 3: N-Formylation of secondary amines by reaction with GCA.
Scheme 4: Synthesis and conversion of hydroxy acetals to cyclic acetals.
Scheme 5: Synthesis of 3-(indol-3-yl)-2,3-dihydrofurans via three-component reaction of glycolaldehyde, indol...
Scheme 6: BiCl3-catalyzed synthesis of benzo[a]carbazoles from 2-arylindoles and α-bromoacetaldehyde ethylene...
Scheme 7: Cu/NCNSs-based conversion of glycerol to glycolic acid and other short biobased acids.
Scheme 8: E. coli-based biotransformation of C1 source molecules (CH4, CO2 and CO) towards C2 glycolic acid.
Scheme 9: N-Formylation of amines with C2 (a) or C3 (b) biomass-based feedstocks.
Scheme 10: Methods for the formation of propanoic acid (PA) from lactic acid (LA).
Scheme 11: Co-polymerization of biobased lactic acid and glycolic acid via a bicatalytic process.
Scheme 12: Oxidation of α-hydroxy acids by tetrachloroaurate(III) in acetic acid–sodium acetate buffer medium.
Figure 2: Selective catalytic pathways for the conversion of lactic acid (LA).
Scheme 13: Synthesis of 1,3-PDO via cross-aldol reaction between formaldehyde and acetaldehyde to 3-hydroxypro...
Scheme 14: Hydrothermal conversion of 1,3-dihydroxy-2-propane and 2,3-dihydroxypropanal to methylglyoxal.
Scheme 15: FLS-catalyzed formose reaction to synthesize GA and DHA.
Scheme 16: GCA and DHA oxidation products of glycerol and isomerization of GCA to DHA under flow conditions us...
Scheme 17: Acid-catalyzed reactions of DHA with alcohols.
Scheme 18: Synthesis of dihydroxyacetone phosphate from dihydroxyacetone.
Scheme 19: Bifunctional acid–base catalyst DHA conversion into lactic acid via pyruvaldehyde or fructose forma...
Scheme 20: Catalytic one-pot synthesis of GA and co-synthesis of formamides and formates from DHA.
Scheme 21: (a) Synthesis of furan derivatives and (b) synthesis of thiophene derivative by cascade [3 + 2] ann...
Scheme 22: Brønsted acidic ionic liquid catalyzed synthesis of benzo[a]carbazole from renewable acetol and 2-p...
Scheme 23: Asymmetric hydrogenation of α-hydroxy ketones to 1,2-diols.
Scheme 24: Synthesis of novel 6-(substituted benzylidene)-2-methylthiazolo [2,3-b]oxazol-5(6H)-one from 1-hydr...
Scheme 25: ʟ-Proline-catalyzed synthesis of anti-diols from hydroxyacetone and aldehydes.
Scheme 26: C–C-bond-formation reactions of a biomass-based feedstock aromatic aldehyde (C5) and hydroxyacetone...
Scheme 27: Ethanol upgrading to C4 bulk chemicals via the thiamine (VB1)-catalyzed acetoin condensation.
Scheme 28: One-pot sequential chemoenzymatic synthesis of 2-aminobutane-1,4-diol and 1,2,4-butanetriol via 1,4...
Scheme 29: Synthesis of 1,4-dihydroxybutan-2-one by microbial transformation.
Scheme 30: Conversion of polyols by [neocuproine)Pd(OAc)]2(OTf)2] to α-hydroxy ketones.
Scheme 31: Chemoselective oxidation of alcohols with chiral palladium-based catalyst 2.
Scheme 32: Electrochemical transformation of furfural to 5-hydroxy-2(5H)-furanone (HFO).
Scheme 33: Selective hydrodeoxygenation of HFO and oxidation to γ-butyrolactone (GBL).
Scheme 34: Photosensitized oxygenation of furan towards HFO via ozonide intermediates.
Scheme 35: Conversion of furfural to HFO and MAN by using mesoporous carbon nitride (SGCN) as photocatalyst.
Scheme 36: Synthesis of HFO from furan derivatives.
Scheme 37: Photooxidation of furfural to 5-hydroxy-2(5H)-furanone (HFO).
Scheme 38: Synthesis of Friedel–Crafts indole adduct from HFO.
Scheme 39: Conversion of HFO to α,γ-substituted chiral γ-lactones.
Scheme 40: Tautomeric transformation of HFO to formylacrylic acid.
Scheme 41: Hydrolysis of HFO to succinic acid in aqueous solution.
Scheme 42: Substitution and condensation reactions of 5-hydroxy-2(5H)-furanone (HFO).
Scheme 43: (a) Conversion of HFO towards valuable C4 chemicals and (b) anodic oxidation of 5-hydroxy-2(5H)-fur...
Figure 3: Conversion of HFO towards other natural and synthetic substances.
Scheme 44: Conversion of furfural to maleic anhydride (reaction a: VOx/Al2O3; reaction b: VPO).
Scheme 45: Conversion of furfural into succinic acid.
Scheme 46: Electro‑, photo‑, and biocatalysis for one-pot selective conversions of furfural into C4 chemicals.
Scheme 47: Production route of furfural from hemicellulose.
Scheme 48: Mechanism for xylose dehydration to furfural through a choline xyloside intermediate.
Scheme 49: Conversion of furfural to furfuryl alcohol and its derivatives.
Scheme 50: Conversion of furfural to furfuryl alcohol and 3-(2-furyl)acrolein.
Scheme 51: The aerobic oxidative condensation of biomass-derived furfural and linear alcohols.
Scheme 52: The single-step synthesis of 2-pentanone from furfural.
Scheme 53: Electrocatalytic coupling reaction of furfural and levulinic acid.
Scheme 54: Conversion of furfural to m-xylylenediamine.
Scheme 55: Conversion of furfural to tetrahydrofuran-derived amines.
Scheme 56: Formation of trans-4,5-diamino-cyclopent-2-enones from furfural.
Scheme 57: Production of pyrrole and proline from furfural.
Scheme 58: Synthesis of 1‑(trifluoromethyl)-8-oxabicyclo[3.2.1]oct-3-en-2-ones from furfural.
Scheme 59: Conversion of furfural to furfural-derived diacids.
Scheme 60: A telescope protocol derived from furfural and glycerol.
Scheme 61: A tandem cyclization of furfural and 5,5-dimethyl-1,3-cyclohexanedione.
Scheme 62: A Ugi four-component reaction to construct furfural-based polyamides.
Scheme 63: One-pot synthesis of γ-acyloxy-Cy7 from furfural.
Scheme 64: Dimerization–Piancatelli sequence toward humins precursors from furfural.
Scheme 65: Conversion of furfural to CPN.
Scheme 66: Synthesis of jet fuels range cycloalkanes from CPN and lignin-derived vanillin.
Scheme 67: Solar-energy-driven synthesis of high-density biofuels from CPN.
Scheme 68: Reductive amination of CPN to cyclopentylamine.
Scheme 69: Asymmetric hydrogenation of C=O bonds of exocyclic α,β-unsaturated cyclopentanones.
Scheme 70: Preparation of levulinic acid via the C5 route (route a) or C6 route (routes b1 and b2).
Scheme 71: Mechanism of the rehydration of HMF to levulinic acid and formic acid.
Scheme 72: Important levulinic acid-derived chemicals.
Scheme 73: Direct conversion of levulinic acid to pentanoic acid.
Scheme 74: Catalytic aerobic oxidation of levulinic acid to citramalic acid.
Scheme 75: Conversion of levulinic acid to 1,4-pentanediol (a) see ref. [236]; b) see ref. [237]; c) see ref. [238]; d) see r...
Scheme 76: Selective production of 2-butanol through hydrogenolysis of levulinic acid.
Scheme 77: General reaction pathways proposed for the formation of 5MPs from levulinic acid.
Scheme 78: Selective reductive amination of levulinic acid to N-substituted pyrroles.
Scheme 79: Reductive amination of levulinic acid to chiral pyrrolidinone.
Scheme 80: Reductive amination of levulinic acid to non-natural chiral γ-amino acid.
Scheme 81: Nitrogen-containing chemicals derived from levulinic acid.
Scheme 82: Preparation of GVL from levulinic acid by dehydration and hydrogenation.
Scheme 83: Ruthenium-catalyzed levulinic acid to chiral γ-valerolactone.
Scheme 84: Catalytic asymmetric hydrogenation of levulinic acid to chiral GVL.
Scheme 85: Three steps synthesis of ε-caprolactam from GVL.
Scheme 86: Multistep synthesis of nylon 6,6 from GVL.
Scheme 87: Preparation of MeGVL by α-alkylation of GVL.
Scheme 88: Ring-opening polymerization of five-membered lactones.
Scheme 89: Synthesis of GVL-based ionic liquids.
Scheme 90: Preparation of butene isomers from GVL under Lewis acid conditions.
Scheme 91: Construction of C5–C12 fuels from GVL over nano-HZSM-5 catalysts.
Scheme 92: Preparation of alkyl valerate from GVL via ring opening/reduction/esterification sequence.
Scheme 93: Construction of 4-acyloxypentanoic acids from GVL.
Scheme 94: Synthesis of 1,4-pentanediol (PDO) from GVL.
Scheme 95: Construction of novel cyclic hemiketal platforms via self-Claisen condensation of GVL.
Scheme 96: Copper-catalyzed lactamization of GVL.
Figure 4: Main scaffolds obtained from HMF.
Scheme 97: Biginelli reactions towards HMF-containing dihydropyrimidinones.
Scheme 98: Hantzsch dihydropyridine synthesis involving HMF.
Scheme 99: The Kabachnik–Fields reaction involving HMF.
Scheme 100: Construction of oxazolidinone from HMF.
Scheme 101: Construction of rhodamine-furan hybrids from HMF.
Scheme 102: A Groebke–Blackburn–Bienaymé reaction involving HMF.
Scheme 103: HMF-containing benzodiazepines by [4 + 2 + 1] cycloadditions.
Scheme 104: Synthesis of fluorinated analogues of α-aryl ketones.
Scheme 105: Synthesis of HMF derived disubstituted γ-butyrolactone.
Scheme 106: Functionalized aromatics from furfural and HMF.
Scheme 107: Diels–Alder adducts from HMF or furfural with N-methylmaleimide.
Scheme 108: Pathway of the one-pot conversion of HMF into phthalic anhydride.
Scheme 109: Photocatalyzed preparation of humins (L-H) from HMF mixed with spoiled HMF residues (LMW-H) and fur...
Scheme 110: Asymmetric dipolar cycloadditions on HMF.
Scheme 111: Dipolar cycloadditions of HMF based nitrones to 3,4- and 3,5-substituted isoxazolidines.
Scheme 112: Production of δ-lactone-fused cyclopenten-2-ones from HMF.
Scheme 113: Aza-Piancatelli access to aza-spirocycles from HMF-derived intermediates.
Scheme 114: Cross-condensation of furfural, acetone and HMF into C13, C14 and C15 products.
Scheme 115: Base-catalyzed aldol condensation/dehydration sequences from HMF.
Scheme 116: Condensation of HMF and active methylene nitrile.
Scheme 117: MBH reactions involving HMF.
Scheme 118: Synthesis of HMF-derived ionic liquids.
Scheme 119: Reductive amination/enzymatic acylation sequence towards HMF-based surfactants.
Scheme 120: The formation of 5-chloromethylfurfural (CMF).
Scheme 121: Conversion of CMF to HMF, levulinic acid, and alkyl levulinates.
Scheme 122: Conversion of CMF to CMFCC and FDCC.
Scheme 123: Conversion of CMF to BHMF.
Scheme 124: Conversion of CMF to DMF.
Scheme 125: CMF chlorine atom substitutions toward HMF ethers and esters.
Scheme 126: Introduction of carbon nucleophiles in CMF.
Scheme 127: NHC-catalyzed remote enantioselective Mannich-type reactions of CMF.
Scheme 128: Conversion of CMF to promising biomass-derived dyes.
Scheme 129: Radical transformation of CMF with styrenes.
Scheme 130: Synthesis of natural herbicide δ-aminolevulinic acid from CMF.
Scheme 131: Four step synthesis of the drug ranitidine from CMF.
Scheme 132: Pd/CO2 cooperative catalysis for the production of HHD and HXD.
Scheme 133: Different ruthenium (Ru) catalysts for the ring-opening of 5-HMF to HHD.
Scheme 134: Proposed pathways for preparing HXD from HMF.
Scheme 135: MCP formation and uses.
Scheme 136: Cu(I)-catalyzed highly selective oxidation of HHD to 2,5-dioxohexanal.
Scheme 137: Synthesis of N‑substituted 3‑hydroxypyridinium salts from 2,5-dioxohexanal.
Scheme 138: Ru catalyzed hydrogenations of HHD to 1,2,5-hexanetriol (a) see ref. [396]; b) see ref. [397]).
Scheme 139: Aviation fuel range quadricyclanes produced by HXD.
Scheme 140: Synthesis of HDGK from HXD and glycerol as a chain extender.
Scheme 141: Synthesis of serinol pyrrole from HXD and serinol.
Scheme 142: Synthesis of pyrroles from HXD and nitroarenes.
Scheme 143: Two-step production of PX from cellulose via HXD.
Scheme 144: Preparation of HCPN from HMF via hydrogenation and ring rearrangement.
Scheme 145: Suggested pathways from HMF to HCPN.
Scheme 146: α-Alkylation of HCPN with ethylene gas.
Scheme 147: Synthesis of 3-(hydroxymethyl)cyclopentylamine from HMF via reductive amination of HCPN.
Scheme 148: Production of LGO and Cyrene® from biomass.
Scheme 149: Synthesis of HBO from LGO and other applications.
Scheme 150: Construction of m-Cyrene® homopolymer.
Scheme 151: Conversion of Cyrene® to THFDM and 1,6-hexanediol.
Scheme 152: RAFT co-polymerization of LGO and butadienes.
Scheme 153: Polycondensation of HO-LGOL and diols with dimethyl adipate.
Scheme 154: Self-condensation of Cyrene® and Claisen–Schmidt reactions.
Scheme 155: Synthesis of 5-amino-2-(hydroxymethyl)tetrahydropyran from Cyrene®.
Beilstein J. Org. Chem. 2025, 21, 1737–1741, doi:10.3762/bjoc.21.136
Graphical Abstract
Scheme 1: Proposed approach for the preparation of vinyloxazoline 6.
Scheme 2: Synthesis of furfuryl amino alcohols S-2d and R-2d and their electrochemical oxidation to esters S-...
Scheme 3: Cleavage of the N-Alloc group leading to a mixture of isomers cis-S-5 and trans-S-5.
Scheme 4: Cleavage of the N-Alloc group with PdCl2(S-BINAP) leading to trans-S-5 and trans-R-5.
Scheme 5: Cyclization of amides trans-S-5 and trans-R-5 to oxazolines S-6 and R-6.
Scheme 6: aza-Diels–Alder reaction of vinyloxazoline S-6 with TsNCO.
Scheme 7: The proposed mechanism of product 7 formation.
Beilstein J. Org. Chem. 2025, 21, 1161–1169, doi:10.3762/bjoc.21.92
Graphical Abstract
Figure 1: Bioactive compounds bearing imidazopyridine (red) and isoquinolinone-kind (blue) rings.
Scheme 1: GBB-initiated synthesis of imidazopyridine-fused isoquinolinones.
Scheme 2: GBB reaction and N-acylation for the preparation of imidazo[1,2-a]pyridines 6.
Scheme 3: Substrate scope for IMDA and dehydrative aromatization in making 8. Reaction conditions: 6 and AlCl3...
Figure 2: Transition state analysis of IMDA reactions for 6a, 6j, 6h and 6r.
Figure 3: Relative energy diagram for the synthesis of 8a from 6a.
Scheme 4: Using thiophene-2-carbaldehyde for the synthesis of 8t.
Scheme 5: Proposed mechanisms for IMDA reaction and dehydration re-aromatization.
Beilstein J. Org. Chem. 2025, 21, 444–450, doi:10.3762/bjoc.21.31
Graphical Abstract
Figure 1: State of the art of Ugi/Diels–Alder reaction based on furan.
Scheme 1: Preparation of 4,4a,5,6,7,7a-hexahydro-3aH-furo[2,3-f]isoindoles via Ugi/IMDAV tandem reaction.
Scheme 2: Kinetic product 5 does not transform into thermodynamic product 6.
Scheme 3: Synthesis of compounds 6a.
Scheme 4: Synthesis of compound 7.
Scheme 5: Synthesis of compounds 9.
Beilstein J. Org. Chem. 2024, 20, 1376–1395, doi:10.3762/bjoc.20.120
Graphical Abstract
Figure 1: Types and mechanism of the Cannizzaro reaction.
Figure 2: Various approaches of the Cannizzaro reaction.
Figure 3: Representative molecules synthesized via the Cannizzaro reaction.
Scheme 1: Intramolecular Cannizzaro reaction of aryl glyoxal hydrates using TOX catalysts.
Scheme 2: Intramolecular Cannizzaro reaction of aryl methyl ketones using ytterbium triflate/selenium dioxide....
Scheme 3: Intramolecular Cannizzaro reaction of aryl glyoxals using Cr(ClO4)3 as catalyst.
Scheme 4: Cu(II)-PhBox-catalyzed asymmetric Cannizzaro reaction.
Scheme 5: FeCl3-based chiral catalyst applied for the enantioselective intramolecular Cannizzaro reaction rep...
Scheme 6: Copper bis-oxazoline-catalysed intramolecular Cannizzaro reaction and proposed mechanism.
Scheme 7: Chiral Fe catalysts-mediated enantioselective Cannizzaro reaction.
Scheme 8: Ruthenium-catalyzed Cannizzaro reaction of aromatic aldehydes.
Scheme 9: MgBr2·Et2O-assisted Cannizzaro reaction of aldehydes.
Scheme 10: LiBr-catalyzed intermolecular Cannizzaro reaction of aldehydes.
Scheme 11: γ-Alumina as a catalyst in the Cannizzaro reaction.
Scheme 12: AlCl3-mediated Cannizzaro disproportionation of aldehydes.
Scheme 13: Ru–N-heterocyclic carbene catalyzed dehydrogenative synthesis of carboxylic acids.
Figure 4: Proposed catalytic cycle for the dehydrogenation of alcohols.
Scheme 14: Intramolecular desymmetrization of tetraethylene glycol.
Scheme 15: Desymmetrization of oligoethylene glycol dialdehydes.
Scheme 16: Intramolecular Cannizzaro reaction of calix[4]arene dialdehydes.
Scheme 17: Desymmetrization of dialdehydes of symmetrical crown ethers using Ba(OH)2.
Scheme 18: Synthesis of ottelione A (proposed) via intramolecular Cannizzaro reaction.
Scheme 19: Intramolecular Cannizzaro reaction for the synthesis of pestalalactone.
Scheme 20: Synthetic strategy towards nigricanin involving an intramolecular Cannizzaro reaction.
Scheme 21: Spiro-β-lactone-γ-lactam part of oxazolomycins via aldol crossed-Cannizzaro reaction.
Scheme 22: Synthesis of indole alkaloids via aldol crossed-Cannizzaro reaction.
Scheme 23: Aldol and crossed-Cannizzaro reaction towards the synthesis of ertuliflozin.
Scheme 24: Synthesis of cyclooctadieneones using a Cannizzaro reaction.
Scheme 25: Microwave-assisted crossed-Cannizzaro reaction for the synthesis of 3,3-disubstituted oxindoles.
Scheme 26: Synthesis of porphyrin-based rings using the Cannizzaro reaction.
Scheme 27: Synthesis of phthalides and pestalalactone via Cannizarro–Tishchenko-type reaction.
Scheme 28: Synthesis of dibenzoheptalene bislactones via a double intramolecular Cannizzaro reaction.
Beilstein J. Org. Chem. 2024, 20, 1308–1319, doi:10.3762/bjoc.20.114
Graphical Abstract
Figure 1: Reaction yields after seven uses of SSO and average recovery of the oil.
Scheme 1: Synthesis of epoxyisoindole-7-carboxylic acids 2a–m and 2n–p.
Scheme 2: Possible side reactions of unsaturated fatty acids with maleic anhydride.
Figure 2: Coupling constants of selected protons in compound 2a and its optimized geometric structure.
Scheme 3: Equilibrium of 2n–p with maleamic acid precursors.
Figure 3: Possible mechanism for the IMDAF reaction.
Figure 4: IRC calculations of a) endo-, b) exo-transition structures and products for compound 2a (semi-empir...
Beilstein J. Org. Chem. 2023, 19, 646–657, doi:10.3762/bjoc.19.46
Graphical Abstract
Figure 1: Biologically active PBTAs.
Scheme 1: Approaches to PBTAs via annulation of benzothiazoles.
Scheme 2: Approaches to PBTAs via annulation of o-aminothiophenols.
Scheme 3: Approach to PBTAs via radical substitution reaction in 1-(2-bromophenyl)-5-(butylsulfanyl)pyrrolidi...
Scheme 4: Approach to PBTAs via intramolecular cyclizations of 1-(2-thiophenyl)pyrroles.
Scheme 5: A new approach to PBTAs via nucleophile-induced ring contraction in pyrrolo[2,1-c][1,4]benzothiazin...
Figure 2: Electrophilic centers in FPDs.
Scheme 6: Reaction of APBTT 1a with methanol (2a).
Scheme 7: Derivatization of PBTA 3aa.
Scheme 8: Reaction of APBTTs 1a–h with alcohols 2a–c. Isolated yields are given; reaction scale: a mixture of ...
Scheme 9: Side-reaction of APBTTs 1 with alcohols 2.
Scheme 10: Transformations of compounds 5 in solutions.
Scheme 11: Reaction of APBTT 1a with benzylamine.
Scheme 12: Derivatization of PBTA 7a.
Scheme 13: Reaction of APBTTs 1a–h and benzylamine. Isolated yields are given; reaction scale: a mixture of 1 ...
Scheme 14: Reaction of APBTT 1a with an excess of benzylamine.
Scheme 15: Reaction of APBTT 1a with morpholine.
Scheme 16: Reaction of APBTT 1a with aniline (11a).
Scheme 17: Derivatization of PBTA 12aa.
Scheme 18: Reaction of APBTTs 1a–h and arylamines 11a–d. Isolated yields are given; reaction scale: a mixture ...
Scheme 19: Side-reaction of APBTT 1a with arylamine 11b.
Scheme 20: Reaction of APBTT 1a with compounds 16a–d.
Scheme 21: Formation of compounds 17 as an undesired process during the synthesis of APBTTs 1.
Beilstein J. Org. Chem. 2023, 19, 582–592, doi:10.3762/bjoc.19.43
Graphical Abstract
Scheme 1: C3-Functionalization of furfural derivatives by C–H activation, a) in batch: previous works, and b)...
Scheme 2: C3-alkylation of bidentate imine 1 performed in batch.
Scheme 3: Optimization of the heating for the alkylation reaction on the homemade pulsed-flow setup.
Scheme 4: Proposed reaction mechanism for the alkylation reaction with formation of ruthenium aggregates and ...
Scheme 5: A) Isolation test of a reaction intermediate; B) XPS and TEM (in ethanol) of the recovered solid ph...
Scheme 6: Ruthenium aggregate-catalyzed alkylation reaction.
Scheme 7: Scope of continuous flow furfural derivative alkylation reaction.
Scheme 8: Scaling up comparison: batch and continuous flow conditions.
Beilstein J. Org. Chem. 2022, 18, 1457–1462, doi:10.3762/bjoc.18.151
Graphical Abstract
Figure 1: Levoglucosenone (1), known dimerization product 2, and adducts 3 and 4.
Scheme 1: Proposed pathway for the formation of 5.
Figure 2: 1H NMR spectra (500 MHz) of 1 (A), 1:1 1/PhCHO reaction mixture at 1 h at 60° C (B), mixture after ...
Scheme 2: Known reactions giving 11, and reactions of dihydrolevoglucosenone 12 and aromatic aldehydes with D...
Beilstein J. Org. Chem. 2022, 18, 1256–1263, doi:10.3762/bjoc.18.131
Graphical Abstract
Scheme 1: C3–Si bond functionalization of biomass-derived 3-silylated furfural platforms.
Scheme 2: Preparation of 3-silylated 2-furyl carbinols.
Scheme 3: C–Si bond functionalization of 2,3-disubstituted furyl carbinols by 1,4-silyl migration.
Scheme 4: Attempts of C3–Si bond functionalization promoted by intramolecular activation via alkoxide.
Scheme 5: Alkoxide-promoted cyclic siloxane formation from 2-[(3-benzyldimethylsilyl)furyl] carbinol 4c.
Scheme 6: TBAF-promoted cyclic siloxane formation from 2-[(3-benzyldimethylsilyl)furyl] carbinol 4c.
Scheme 7: Pd-catalyzed arylation of 2-[(3-benzyldimethylsilyl)furyl] carbinol 4c.
Scheme 8: Cu-catalyzed allylation and methylation of 2-[(3-benzyldimethylsilyl)furyl] carbinols. aCuI⋅PPh3 (1...
Beilstein J. Org. Chem. 2021, 17, 2462–2476, doi:10.3762/bjoc.17.163
Graphical Abstract
Scheme 1: Ag/I2-mediated electrophilic annulation of 2-en-4-ynyl azides 1.
Scheme 2: The proposed mechanism of Ag-catalyzed aza-annulation.
Scheme 3: The proposed mechanism of I2-mediated aza-annulation.
Scheme 4: Copper-catalyzed amination of (E)-2-en-4-ynyl azides 1.
Scheme 5: The proposed mechanism of copper-catalyzed amination.
Scheme 6: The derivatization of sulfonated aminonicotinates.
Scheme 7: Copper-catalyzed chalcogenoamination of (E)-2-en-4-ynyl azides 1.
Scheme 8: The possible mechanism of chalcogenoamination.
Scheme 9: The derivatization of 5‑selenyl- and 5-sulfenyl-substituted nicotinates.
Scheme 10: The tandem reaction of nitriles, Reformatsky reagents, and 1,3-enynes.
Scheme 11: Nickel-catalyzed [4 + 2]-cycloaddition of 3-azetidinones with 1,3-enynes.
Scheme 12: Electrophilic iodocyclization of 2-nitro-1,3-enynes to pyrroles.
Scheme 13: Electrophilic halogenation of 2-trifluoromethyl-1,3-enynes to pyrroles.
Scheme 14: Copper-catalyzed cascade cyclization of 2-nitro-1,3-enynes with amines.
Scheme 15: Tandem cyclization of 2-nitro-1,3-enynes, Togni reagent II, and amines.
Scheme 16: Tandem cyclization of 2-nitro-1,3-enynes, TMSN3, and amines.
Scheme 17: Cascade cyclization of 6-hydroxyhex-2-en-4-ynals to pyrroles.
Scheme 18: Au/Ag-catalyzed oxidative aza-annulation of 1,3-enynyl azides.
Scheme 19: The plausible mechanism of Au/Ag-catalyzed oxidative aza-annulation.
Scheme 20: Synthesis of 2-tetrazolyl-substituted 3-acylpyrroles from enynals.
Scheme 21: CuH-catalyzed coupling reaction of 1,3-enynes and nitriles to pyrroles.
Scheme 22: The mechanism of CuH-catalyzed coupling of 1,3-enynes and nitriles to pyrroles.
Beilstein J. Org. Chem. 2021, 17, 1952–1980, doi:10.3762/bjoc.17.128
Graphical Abstract
Figure 1: Coumarin-derived commercially available drugs.
Figure 2: Inhibition of acetylcholinesterase by coumarin derivatives.
Scheme 1: Michael addition of 4-hydroxycoumarins 1 to α,β‐unsaturated enones 2.
Scheme 2: Organocatalytic conjugate addition of 4-hydroxycoumarin 1 to α,β-unsaturated aldehydes 2 followed b...
Scheme 3: Synthesis of 3,4-dihydrocoumarin derivatives 10 through decarboxylative and dearomatizative cascade...
Scheme 4: Total synthesis of (+)-smyrindiol (17).
Scheme 5: Michael addition of 4-hydroxycoumarin (1) to enones 2 through a bifunctional modified binaphthyl or...
Scheme 6: Michael addition of ketones 20 to 3-aroylcoumarins 19 using a cinchona alkaloid-derived primary ami...
Scheme 7: Enantioselective reaction of cyclopent-2-enone-derived MBH alcohols 24 with 4-hydroxycoumarins 1.
Scheme 8: Sequential Michael addition/hydroalkoxylation one-pot approach to annulated coumarins 28 and 30.
Scheme 9: Michael addition of 4-hydroxycoumarins 1 to enones 2 using a binaphthyl diamine catalyst 31.
Scheme 10: Asymmetric Michael addition of 4-hydroxycoumarin 1 with α,β-unsaturated ketones 2 catalyzed by a ch...
Scheme 11: Catalytic asymmetric β-C–H functionalization of ketones via enamine oxidation.
Scheme 12: Enantioselective synthesis of polycyclic coumarin derivatives 37 catalyzed by an primary amine-imin...
Scheme 13: Allylic alkylation reaction between 3-cyano-4-methylcoumarins 39 and MBH carbonates 40.
Scheme 14: Enantioselective synthesis of cyclopropa[c]coumarins 45.
Scheme 15: NHC-catalyzed lactonization of 2-bromoenals 46 with 4-hydroxycoumarin (1).
Scheme 16: NHC-catalyzed enantioselective synthesis of dihydrocoumarins 51.
Scheme 17: Domino reaction of enals 2 with hydroxylated malonate 53 catalyzed by NHC 55.
Scheme 18: Oxidative [4 + 2] cycloaddition of enals 57 to coumarins 56 catalyzed by NHC 59.
Scheme 19: Asymmetric [3 + 2] cycloaddition of coumarins 43 to azomethine ylides 60 organocatalyzed by quinidi...
Scheme 20: Synthesis of α-benzylaminocoumarins 64 through Mannich reaction between 4-hydroxycoumarins (1) and ...
Scheme 21: Asymmetric addition of malonic acid half-thioesters 67 to coumarins 66 using the sulphonamide organ...
Scheme 22: Enantioselective 1,4-addition of azadienes 71 to 3-homoacyl coumarins 70.
Scheme 23: Michael addition/intramolecular cyclization of 3-acylcoumarins 43 to 3-halooxindoles 74.
Scheme 24: Enantioselective synthesis of 3,4-dihydrocoumarins 78 catalyzed by squaramide 73.
Scheme 25: Organocatalyzed [4 + 2] cycloaddition between 2,4-dienals 79 and 3-coumarincarboxylates 43.
Scheme 26: Enantioselective one-pot Michael addition/intramolecular cyclization for the synthesis of spiro[dih...
Scheme 27: Michael/hemiketalization addition enantioselective of hydroxycoumarins (1) to: (a) enones 2 and (b)...
Scheme 28: Synthesis of 2,3-dihydrofurocoumarins 89 through Michael addition of 4-hydroxycoumarins 1 to β-nitr...
Scheme 29: Synthesis of pyrano[3,2-c]chromene derivatives 93 via domino reaction between 4-hydroxycoumarins (1...
Scheme 30: Conjugated addition of 4-hydroxycoumarins 1 to nitroolefins 95.
Scheme 31: Michael addition of 4-hydroxycoumarin 1 to α,β-unsaturated ketones 2 promoted by primary amine thio...
Scheme 32: Enantioselective synthesis of functionalized pyranocoumarins 99.
Scheme 33: 3-Homoacylcoumarin 70 as 1,3-dipole for enantioselective concerted [3 + 2] cycloaddition.
Scheme 34: Synthesis of warfarin derivatives 107 through addition of 4-hydroxycoumarins 1 to β,γ-unsaturated α...
Scheme 35: Asymmetric multicatalytic reaction sequence of 2-hydroxycinnamaldehydes 109 with 4-hydroxycoumarins ...
Scheme 36: Mannich asymmetric addition of cyanocoumarins 39 to isatin imines 112 catalyzed by the amide-phosph...
Scheme 37: Enantioselective total synthesis of (+)-scuteflorin A (119).
Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90
Graphical Abstract
Figure 1: Representative shares of the global F&F market (2018) segmented on their applications [1].
Figure 2: General structure of an international fragrance company [2].
Figure 3: The Michael Edwards fragrance wheel.
Figure 4: Examples of oriental (1–3), woody (4–7), fresh (8–10), and floral (11 and 12) notes.
Figure 5: A basic depiction of batch vs flow.
Scheme 1: Examples of reactions for which flow processing outperforms batch.
Scheme 2: Some industrially important aldol-based transformations.
Scheme 3: Biphasic continuous aldol reactions of acetone and various aldehydes.
Scheme 4: Aldol synthesis of 43 in flow using LiHMDS as the base.
Scheme 5: A semi-continuous synthesis of doravirine (49) involving a key aldol reaction.
Scheme 6: Enantioselective aldol reaction using 5-(pyrrolidin-2-yl)tetrazole (51) as catalyst in a microreact...
Scheme 7: Gröger's example of asymmetric aldol reaction in aqueous media.
Figure 6: Immobilised reagent column reactor types.
Scheme 8: Photoinduced thiol–ene coupling preparation of silica-supported 5-(pyrrolidin-2-yl)tetrazole 63 and...
Scheme 9: Continuous-flow approach for enantioselective aldol reactions using the supported catalyst 67.
Scheme 10: Ötvös’ employment of a solid-supported peptide aldol catalyst in flow.
Scheme 11: The use of proline tetrazole packed in a column for aldol reaction between cyclohexanone (65) and 2...
Scheme 12: Schematic diagram of an aminosilane-grafted Si-Zr-Ti/PAI-HF reactor for continuous-flow aldol and n...
Scheme 13: Continuous-flow condensation for the synthesis of the intermediate 76 to nabumetone (77) and Microi...
Scheme 14: Synthesis of ψ-Ionone (80) in continuous-flow via aldol condensation between citral (79) and aceton...
Scheme 15: Synthesis of β-methyl-ionones (83) from citral (79) in flow. The steps are separately described, an...
Scheme 16: Continuous-flow synthesis of 85 from 84 described by Gavriilidis et al.
Scheme 17: Continuous-flow scCO2 apparatus for the synthesis of 2-methylpentanal (87) and the self-condensed u...
Scheme 18: Chen’s two-step flow synthesis of coumarin (90).
Scheme 19: Pechmann condensation for the synthesis of 7-hydroxyxcoumarin (93) in flow. The setup extended to c...
Scheme 20: Synthesis of the dihydrojasmonate 35 exploiting nitro derivative proposed by Ballini et al.
Scheme 21: Silica-supported amines as heterogeneous catalyst for nitroaldol condensation in flow.
Scheme 22: Flow apparatus for the nitroaldol condensation of p-hydroxybenzaldehyde (102) to nitrostyrene 103 a...
Scheme 23: Nitroaldol reaction of 64 to 105 employing a quaternary ammonium functionalised PANF.
Scheme 24: Enantioselective nitroaldol condensation for the synthesis of 108 under flow conditions.
Scheme 25: Enatioselective synthesis of 1,2-aminoalcohol 110 via a copper-catalysed nitroaldol condensation.
Scheme 26: Examples of Knoevenagel condensations applied for fragrance components.
Scheme 27: Flow apparatus for Knoevenagel condensation described in 1989 by Venturello et al.
Scheme 28: Knoevenagel reaction using a coated multichannel membrane microreactor.
Scheme 29: Continuous-flow apparatus for Knoevenagel condensation employing sugar cane bagasse as support deve...
Scheme 30: Knoevenagel reaction for the synthesis of 131–135 in flow using an amine-functionalised silica gel. ...
Scheme 31: Continuous-flow synthesis of compound 137, a key intermediate for the synthesis of pregabalin (138)...
Scheme 32: Continuous solvent-free apparatus applied for the synthesis of compounds 140–143 using a TSE. Throu...
Scheme 33: Lewis et al. developed a spinning disc reactor for Darzens condensation of 144 and a ketone to furn...
Scheme 34: Some key industrial applications of conjugate additions in the F&F industry.
Scheme 35: Continuous-flow synthesis of 4-(2-hydroxyethyl)thiomorpholine 1,1-dioxide (156) via double conjugat...
Scheme 36: Continuous-flow system for Michael addition using CsF on alumina as the catalyst.
Scheme 37: Calcium chloride-catalysed asymmetric Michael addition using an immobilised chiral ligand.
Scheme 38: Continuous multistep synthesis for the preparation of (R)-rolipram (173). Si-NH2: primary amine-fun...
Scheme 39: Continuous-flow Michael addition using ion exchange resin Amberlyst® A26.
Scheme 40: Preparation of the heterogeneous catalyst 181 developed by Paixão et al. exploiting Ugi multicompon...
Scheme 41: Continuous-flow system developed by the Paixão’s group for the preparation of Michael asymmetric ad...
Scheme 42: Continuous-flow synthesis of nitroaldols catalysed by supported catalyst 184 developed by Wennemers...
Scheme 43: Heterogenous polystyrene-supported catalysts developed by Pericàs and co-workers.
Scheme 44: PANF-supported pyrrolidine catalyst for the conjugate addition of cyclohexanone (65) and trans-β-ni...
Scheme 45: Synthesis of (−)-paroxetine precursor 195 developed by Ötvös, Pericàs, and Kappe.
Scheme 46: Continuous-flow approach for the 5-step synthesis of (−)-oseltamivir (201) as devised by Hayashi an...
Scheme 47: Continuous-flow enzyme-catalysed Michael addition.
Scheme 48: Continuous-flow copper-catalysed 1,4 conjugate addition of Grignard reagents to enones. Reprinted w...
Scheme 49: A collection of commonly encountered hydrogenation reactions.
Figure 7: The ThalesNano H-Cube® continuous-flow hydrogenator.
Scheme 50: Chemoselective reduction of an α,β-unsaturated ketone using the H-Cube® reactor.
Scheme 51: Incorporation of Lindlar’s catalyst into the H-Cube® reactor for the reduction of an alkyne.
Scheme 52: Continuous-flow semi-hydrogenation of alkyne 208 to 209 using SACs with H-Cube® system.
Figure 8: The standard setups for tube-in-tube gas–liquid reactor units.
Scheme 53: Homogeneous hydrogenation of olefins using a tube-in-tube reactor setup.
Scheme 54: Recyclable heterogeneous flow hydrogenation system.
Scheme 55: Leadbeater’s reverse tube-in-tube hydrogenation system for olefin reductions.
Scheme 56: a) Hydrogenation using a Pd-immobilised microchannel reactor (MCR) and b) a representation of the i...
Scheme 57: Hydrogenation of alkyne 238 exploiting segmented flow in a Pd-immobilised capillary reactor.
Scheme 58: Continuous hydrogenation system for the preparation of cyrene (241) from (−)-levoglucosenone (240).
Scheme 59: Continuous hydrogenation system based on CSMs developed by Hornung et al.
Scheme 60: Chemoselective reduction of carbonyls (ketones over aldehydes) in flow.
Scheme 61: Continuous system for the semi-hydrogenation of 256 and 258, developed by Galarneau et al.
Scheme 62: Continuous synthesis of biodiesel fuel 261 from lignin-derived furfural acetone (260).
Scheme 63: Continuous synthesis of γ-valerolacetone (263) via CTH developed by Pineda et al.
Scheme 64: Continuous hydrogenation of lignin-derived biomass (products 265, 266, and 267) using a sustainable...
Scheme 65: Ru/C or Rh/C-catalysed hydrogenation of arene in flow as developed by Sajiki et al.
Scheme 66: Polysilane-immobilized Rh–Pt-catalysed hydrogenation of arenes in flow by Kobayashi et al.
Scheme 67: High-pressure in-line mixing of H2 for the asymmetric reduction of 278 at pilot scale with a 73 L p...
Figure 9: Picture of the PFR employed at Eli Lilly & Co. for the continuous hydrogenation of 278 [287]. Reprinted ...
Scheme 68: Continuous-flow asymmetric hydrogenation using Oppolzer's sultam 280 as chiral auxiliary.
Scheme 69: Some examples of industrially important oxidation reactions in the F&F industry. CFL: compact fluor...
Scheme 70: Gold-catalysed heterogeneous oxidation of alcohols in flow.
Scheme 71: Uozumi’s ARP-Pt flow oxidation protocol.
Scheme 72: High-throughput screening of aldehyde oxidation in flow using an in-line GC.
Scheme 73: Permanganate-mediated Nef oxidation of nitroalkanes in flow with the use of in-line sonication to p...
Scheme 74: Continuous-flow aerobic anti-Markovnikov Wacker oxidation.
Scheme 75: Continuous-flow oxidation of 2-benzylpyridine (312) using air as the oxidant.
Scheme 76: Continuous-flow photo-oxygenation of monoterpenes.
Scheme 77: A tubular reactor design for flow photo-oxygenation.
Scheme 78: Glucose oxidase (GOx)-mediated continuous oxidation of glucose using compressed air and the FFMR re...
Scheme 79: Schematic continuous-flow sodium hypochlorite/TEMPO oxidation of alcohols.
Scheme 80: Oxidation using immobilised TEMPO (344) was developed by McQuade et al.
Scheme 81: General protocol for the bleach/catalytic TBAB oxidation of aldehydes and alcohols.
Scheme 82: Continuous-flow PTC-assisted oxidation using hydrogen peroxide. The process was easily scaled up by...
Scheme 83: Continuous-flow epoxidation of cyclohexene (348) and in situ preparation of m-CPBA.
Scheme 84: Continuous-flow epoxidation using DMDO as oxidant.
Scheme 85: Mukayama aerobic epoxidation optimised in flow mode by the Favre-Réguillon group.
Scheme 86: Continuous-flow asymmetric epoxidation of derivatives of 359 exploiting a biomimetic iron catalyst.
Scheme 87: Continuous-flow enzymatic epoxidation of alkenes developed by Watts et al.
Scheme 88: Engineered multichannel microreactor for continuous-flow ozonolysis of 366.
Scheme 89: Continuous-flow synthesis of the vitamin D precursor 368 using multichannel microreactors. MFC: mas...
Scheme 90: Continuous ozonolysis setup used by Kappe et al. for the synthesis of various substrates employing ...
Scheme 91: Continuous-flow apparatus for ozonolysis as developed by Ley et al.
Scheme 92: Continuous-flow ozonolysis for synthesis of vanillin (2) using a film-shear flow reactor.
Scheme 93: Examples of preparative methods for ajoene (386) and allicin (388).
Scheme 94: Continuous-flow oxidation of thioanisole (389) using styrene-based polymer-supported peroxytungstat...
Scheme 95: Continuous oxidation of thiosulfinates using Oxone®-packed reactor.
Scheme 96: Continuous-flow electrochemical oxidation of thioethers.
Scheme 97: Continuous-flow oxidation of 400 to cinnamophenone (235).
Scheme 98: Continuous-flow synthesis of dehydrated material 401 via oxidation of methyl dihydrojasmonate (33).
Scheme 99: Some industrially important transformations involving Grignard reagents.
Scheme 100: Grachev et al. apparatus for continuous preparation of Grignard reagents.
Scheme 101: Example of fluidized Mg bed reactor with NMR spectrometer as on-line monitoring system.
Scheme 102: Continuous-flow synthesis of Grignard reagents and subsequent quenching reaction.
Figure 10: Membrane-based, liquid–liquid separator with integrated pressure control [52]. Adapted with permission ...
Scheme 103: Continuous-flow synthesis of 458, an intermediate to fluconazole (459).
Scheme 104: Continuous-flow synthesis of ketones starting from benzoyl chlorides.
Scheme 105: A Grignard alkylation combining CSTR and PFR technologies with in-line infrared reaction monitoring....
Scheme 106: Continuous-flow preparation of 469 from Grignard addition of methylmagnesium bromide.
Scheme 107: Continuous-flow synthesis of Grignard reagents 471.
Scheme 108: Preparation of the Grignard reagent 471 using CSTR and the continuous process for synthesis of the ...
Scheme 109: Continuous process for carboxylation of Grignard reagents in flow using tube-in-tube technology.
Scheme 110: Continuous synthesis of propargylic alcohols via ethynyl-Grignard reagent.
Scheme 111: Silica-supported catalysed enantioselective arylation of aldehydes using Grignard reagents in flow ...
Scheme 112: Acid-catalysed rearrangement of citral and dehydrolinalool derivatives.
Scheme 113: Continuous stilbene isomerisation with continuous recycling of photoredox catalyst.
Scheme 114: Continuous-flow synthesis of compound 494 as developed by Ley et al.
Scheme 115: Selected industrial applications of DA reaction.
Scheme 116: Multistep flow synthesis of the spirocyclic structure 505 via employing DA cycloaddition.
Scheme 117: Continuous-flow DA reaction developed in a plater flow reactor for the preparation of the adduct 508...
Scheme 118: Continuous-flow DA reaction using a silica-supported imidazolidinone organocatalyst.
Scheme 119: Batch vs flow for the DA reaction of (cyclohexa-1,5-dien-1-yloxy)trimethylsilane (513) with acrylon...
Scheme 120: Continuous-flow DA reaction between 510 and 515 using a shell-core droplet system.
Scheme 121: Continuous-flow synthesis of bicyclic systems from benzyne precursors.
Scheme 122: Continuous-flow synthesis of bicyclic scaffolds 527 and 528 for further development of potential ph...
Scheme 123: Continuous-flow inverse-electron hetero-DA reaction to pyridine derivatives such as 531.
Scheme 124: Comparison between batch and flow for the synthesis of pyrimidinones 532–536 via retro-DA reaction ...
Scheme 125: Continuous-flow coupled with ultrasonic system for preparation of ʟ-ascorbic acid derivatives 539 d...
Scheme 126: Two-step continuous-flow synthesis of triazole 543.
Scheme 127: Continuous-flow preparation of triazoles via CuAAC employing 546-based heterogeneous catalyst.
Scheme 128: Continuous-flow synthesis of compounds 558 through A3-coupling and 560 via AgAAC both employing the...
Scheme 129: Continuous-flow photoinduced [2 + 2] cycloaddition for the preparation of bicyclic derivatives of 5...
Scheme 130: Continuous-flow [2 + 2] and [5 + 2] cycloaddition on large scale employing a flow reactor developed...
Scheme 131: Continuous-flow preparation of the tricyclic structures 573 and 574 starting from pyrrole 570 via [...
Scheme 132: Continuous-flow [2 + 2] photocyclization of cinnamates.
Scheme 133: Continuous-flow preparation of cyclobutane 580 on a 5-plates photoreactor.
Scheme 134: Continuous-flow [2 + 2] photocycloaddition under white LED lamp using heterogeneous PCN as photocat...
Figure 11: Picture of the parallel tube flow reactor (PTFR) "The Firefly" developed by Booker-Milburn et al. a...
Scheme 135: Continuous-flow acid-catalysed [2 + 2] cycloaddition between silyl enol ethers and acrylic esters.
Scheme 136: Continuous synthesis of lactam 602 using glass column reactors.
Scheme 137: In situ generation of ketenes for the Staudinger lactam synthesis developed by Ley and Hafner.
Scheme 138: Application of [2 + 2 + 2] cycloadditions in flow employed by Ley et al.
Scheme 139: Examples of FC reactions applied in F&F industry.
Scheme 140: Continuous-flow synthesis of ibuprofen developed by McQuade et al.
Scheme 141: The FC acylation step of Jamison’s three-step ibuprofen synthesis.
Scheme 142: Synthesis of naphthalene derivative 629 via FC acylation in microreactors.
Scheme 143: Flow system for rapid screening of catalysts and reaction conditions developed by Weber et al.
Scheme 144: Continuous-flow system developed by Buorne, Muller et al. for DSD optimisation of the FC acylation ...
Scheme 145: Continuous-flow FC acylation of alkynes to yield β-chlorovinyl ketones such as 638.
Scheme 146: Continuous-flow synthesis of tonalide (619) developed by Wang et al.
Scheme 147: Continuous-flow preparation of acylated arene such as 290 employing Zr4+-β-zeolite developed by Kob...
Scheme 148: Flow system applied on an Aza-FC reaction catalysed by the thiourea catalyst 648.
Scheme 149: Continuous hydroformylation in scCO2.
Scheme 150: Two-step flow synthesis of aldehyde 655 through a sequential Heck reaction and subsequent hydroform...
Scheme 151: Single-droplet (above) and continuous (below) flow reactors developed by Abolhasani et al. for the ...
Scheme 152: Continuous hydroformylation of 1-dodecene (655) using a PFR-CSTR system developed by Sundmacher et ...
Scheme 153: Continuous-flow synthesis of the aldehyde 660 developed by Eli Lilly & Co. [32]. Adapted with permissio...
Scheme 154: Continuous asymmetric hydroformylation employing heterogenous catalst supported on carbon-based sup...
Scheme 155: Examples of acetylation in F&F industry: synthesis of bornyl (S,R,S-664) and isobornyl (S,S,S-664) ...
Scheme 156: Continuous-flow preparation of bornyl acetate (S,R,S-664) employing the oscillating flow reactor.
Scheme 157: Continuous-flow synthesis of geranyl acetate (666) from acetylation of geraniol (343) developed by ...
Scheme 158: 12-Ttungstosilicic acid-supported silica monolith-catalysed acetylation in flow.
Scheme 159: Continuous-flow preparation of cyclopentenone 676.
Scheme 160: Two-stage synthesis of coumarin (90) via acetylation of salicylaldehyde (88).
Scheme 161: Intensification process for acetylation of 5-methoxytryptamine (677) to melatonin (678) developed b...
Scheme 162: Examples of macrocyclic musky odorants both natural (679–681) and synthetic (682 and 683).
Scheme 163: Flow setup combined with microwave for the synthesis of macrocycle 686 via RCM.
Scheme 164: Continuous synthesis of 2,5-dihydro-1H-pyrroles via ring-closing metathesis.
Scheme 165: Continuous-flow metathesis of 485 developed by Leadbeater et al.
Figure 12: Comparison between RCM performed using different routes for the preparation of 696. On the left the...
Scheme 166: Continuous-flow RCM of 697 employed the solid-supported catalyst 698 developed by Grela, Kirschning...
Scheme 167: Continuous-flow RORCM of cyclooctene employing the silica-absorbed catalyst 700.
Scheme 168: Continuous-flow self-metathesis of methyl oleate (703) employing SILP catalyst 704.
Scheme 169: Flow apparatus for the RCM of 697 using a nanofiltration membrane for the recovery and reuse of the...
Scheme 170: Comparison of loadings between RCMs performed with different routes for the synthesis of 709.
Beilstein J. Org. Chem. 2021, 17, 420–430, doi:10.3762/bjoc.17.38
Graphical Abstract
Scheme 1: Sulfur metabolism in bacteria from the roseobacter group. A) DMSP demethylation by DmdABCD, B) DMSP...
Figure 1: Total ion chromatograms of headspace extracts from A) C. marinus DSM 100036T, B) C. neptunius DSM 2...
Figure 2: Structures of the identified volatile compounds in the headspace extracts from six Celeribacter typ...
Figure 3: EI mass spectra of A) unlabeled 2-(methyldisulfanyl)benzothiazole (41) and of labeled 41 after feed...
Scheme 2: Synthesis of sulfur-containing compounds detected in the Celeribacter headspace extracts. A) Synthe...
Beilstein J. Org. Chem. 2019, 15, 1786–1794, doi:10.3762/bjoc.15.172
Graphical Abstract
Scheme 1: Oxidation of 3-pheny-1-propanol (1a) with N-chlorosuccinimide (NCS) in the presence of (2,2,6,6-tet...
Scheme 2: Hypothesized pathways for the TEMPO-assisted oxidation of alcohols in a) basic or b) acidic reactio...
Scheme 3: TEMPO-assisted oxidation of 3-pheny-1-propanol (1a) under mechanical activation conditions. aPercen...
Scheme 4: Scope of primary alcohol oxidation under mechanical activation conditions. aAll yields refer to iso...
Scheme 5: Proposed mechanism for the oxidation of benzylic alcohols 6a and 7a under mechanochemical condition...
Scheme 6: Scope of secondary alcohols in the oxidation under mechanical activation conditions. aAll yields re...
Scheme 7: Possible mechanism for the TEMPO-mediated oxidation of primary and secondary alcohols by using NaOC...
Beilstein J. Org. Chem. 2019, 15, 1210–1216, doi:10.3762/bjoc.15.118
Graphical Abstract
Scheme 1: Schematic synthesis of polyfurfulyl alcohol (PFA) incorporating a prolyl peptide catalyst. AA: Amin...
Scheme 2: Utilization of the Ugi four-component reaction (Ugi-4CR) for the synthesis of prolyl pseudo-peptide...
Figure 1: Analysis of the continuous-flow catalytic system producing γ-nitroaldehyde 5 with PFA-supported cat...
Beilstein J. Org. Chem. 2018, 14, 2846–2852, doi:10.3762/bjoc.14.263
Graphical Abstract
Scheme 1: α-Amino esters from ethyl nitroacetate (4).
Scheme 2: Preparations of α-amino esters 10, 12 and 14.
Scheme 3: Syntheses of α-amino ester 18 and piperazinediones 23a,b.
Scheme 4: Syntheses of α-hydroximino ester 29 and α-amino ester 36.
Scheme 5: Synthesis of α-amino ester 43.
Beilstein J. Org. Chem. 2018, 14, 2745–2770, doi:10.3762/bjoc.14.253
Graphical Abstract
Figure 1: Different types of sulfonated materials as acid catalysts.
Scheme 1: Synthetic route of 3-methyl-1-sulfo-1H-imidazolium metal chloride ILs and their catalytic applicati...
Scheme 2: Synthetic route of 1,3-disulfo-1H-imidazolium transition metal chloride ILs and their catalytic app...
Scheme 3: Synthetic route of 1,3-disulfoimidazolium carboxylate ILs and their catalytic applications in the s...
Scheme 4: Synthetic route of [BiPy](HSO3)2Cl2 and [Dsim]HSO4 ILs and their catalytic applications for the syn...
Scheme 5: The catalytic applications of (C4(DABCO-SO3H)2·4Cl) IL for the synthesis of spiro-isatin derivative...
Scheme 6: The catalytic applications of (C4(DABCO-SO3H)2·4Cl) IL for the synthesis of bis 2-amino-4H-pyran de...
Scheme 7: The synthetic route of N,N-disulfo-1,1,3,3-tetramethylguanidinium carboxylate ILs and their catalyt...
Scheme 8: The catalytic application of 1-methyl-3-sulfo-1H-imidazolium tetrachloroferrate IL in the synthesis...
Scheme 9: The synthetic route of 3-sulfo-1H-imidazolopyrimidinium hydrogen sulfate IL and its catalytic appli...
Scheme 10: The results for the synthesis of bis(indolyl)methanes and di(bis(indolyl)methyl)benzenes in the pre...
Scheme 11: The catalytic applications of 1-(1-sulfoalkyl)-3-methylimidazolium chloride acidic ILs for the hydr...
Scheme 12: The synthetic route of immobilized 1,4-diazabicyclo[2.2.2]octanesulfonic acid chloride on SiO2 and ...
Scheme 13: The catalytic application of a silica-bonded sulfoimidazolium chloride for the synthesis of 12-aryl...
Scheme 14: The synthetic route of the SBA-15-Ph-SO3H and its catalytic applications for the synthesis of 2H-in...
Scheme 15: The synthetic route for heteropolyanion-based ionic liquids immobilized on mesoporous silica SBA-15...
Scheme 16: Some mechanism aspects of SSA catalyst for the protection of amine derivatives.
Scheme 17: The synthetic route for MWCNT-SO3H and its catalytic application for the synthesis of N-substituted...
Scheme 18: The sulfonic acid-functionalized polymers (P-SO3H) covalently grafted on multi-walled carbon nanotu...
Scheme 19: The transesterification reaction in the presence of S-MWCNTs.
Scheme 20: The synthetic route for the new hypercrosslinked supermicroporous polymer via the Friedel–Crafts al...
Scheme 21: The synthetic route for a new microporous copolymer via the Friedel–Crafts alkylation reaction of t...
Scheme 22: The synthetic route for sulfonated polynaphthalene and its catalytic application for the amidoalkyl...
Scheme 23: The synthetic route of the acidic carbon material and its catalytic application in the etherificatio...
Scheme 24: The synthetic route of the acidic carbon materials and their catalytic applications for the esterif...
Scheme 25: The sulfonated MWCNTs.
Scheme 26: The sulfonated nanoscaled diamond powder for the dehydration of D-xylose into furfural.
Scheme 27: The synthetic route and catalytic application of the GR-SO3H.
Beilstein J. Org. Chem. 2018, 14, 325–344, doi:10.3762/bjoc.14.21
Graphical Abstract
Scheme 1: Reformatsky-type reaction.
Scheme 2: First total synthesis of prunustatin A based on a Zn-mediated Reformatsky reaction [17].
Scheme 3: Synthesis of a γ-hydroxylysine derivative through a Zn-mediated nitrile Reformatsky-type reaction [18].
Scheme 4: Synthesis of apratoxin E and its C30 epimer through a Zn-mediated Reformatsky reaction. Fmoc = 9-fl...
Scheme 5: Synthesis of the eastern fragment of jatrophane diterpene Pl-3 through a SmI2-mediated Reformatsky ...
Scheme 6: First total synthesis of prebiscibactin through a SmI2-mediated Reformatsky reaction. Boc = tert-bu...
Scheme 7: Synthesis of prostaglandin E2 methyl ester through a SmI2-mediated Reformatsky reaction [23].
Scheme 8: Synthesis of the C1–C11 fragment of tedanolide C through a SnCl2-mediated Reformatsky reaction. PMB...
Scheme 9: Synthesis of β-trifluoromethyl β-(N-tert-butylsulfinyl)amino esters exhibiting a quaternary stereoc...
Scheme 10: Synthesis of α,α-difluoro-β-(N-tert-butylsulfinyl)amino esters through Zn(II)-mediated aza-Reformat...
Scheme 11: Synthesis of a common fragment to anti-apoptotic protein inhibitors through a Zn-mediated aza-Refor...
Scheme 12: Synthesis of α,α-difluoro-β-(N-tert-butylsulfinyl)amino ketones through a Zn-mediated aza-Reformats...
Scheme 13: Synthesis of (2-oxoindolin-3-yl)amino esters through a Zn-mediated aza-Reformatsky reaction [30].
Scheme 14: Synthesis of a precursor of sacubitril through a Zn-mediated aza-Reformatsky reaction [31].
Scheme 15: Synthesis of epothilone D through a Cr(II)-mediated Reformatsky reaction. TFA = trifluoroacetic aci...
Scheme 16: Synthesis of β-hydroxy-α-methyl-δ-trichloromethyl-δ-valerolactone through a Sm(II)- or Yb(II)-media...
Scheme 17: Synthesis of cebulactam A1 through a Sm(II)-mediated Reformatsky reaction. MOM = methoxymethyl [34].
Scheme 18: Synthesis of ansamacrolactams (+)-Q-1047H-A-A and (+)-Q-1047H-R-A through a Sm(II)-mediated Reforma...
Scheme 19: Reformatsky reaction of aldehydes with ethyl iodoacetate in the presence of a chiral 1,2-amino alco...
Scheme 20: Reformatsky reaction of aldehydes with ethyl bromoacetate in the presence of a chiral amide ligand [44]....
Scheme 21: Reformatsky reaction of cinnamaldehyde with ethyl bromozinc-α,α-difluoroacetate in the presence of ...
Scheme 22: Reformatsky reaction of aldehydes with an enolate equivalent prepared from phenyl isocyanate and CH2...
Scheme 23: Domino aza-Reformatsky/cyclization reactions of imines with ethyl dibromofluoroacetate in the prese...
Scheme 24: Domino aza-Reformatsky/cyclization reactions of imines with ethyl bromodifluoroacetate in the prese...
Scheme 25: Aza-Reformatsky reactions of cyclic imines with ethyl iodoacetate in the presence of a chiral diary...
Scheme 26: Mechanism for aza-Reformatsky reaction of cyclic imines with ethyl iodoacetate in the presence of a...
Scheme 27: Aza-Reformatsky reaction of dibenzo[b,f][1,4]oxazepines and dibenzo[b,f][1,4]thiazepine with ethyl ...
Beilstein J. Org. Chem. 2017, 13, 2235–2251, doi:10.3762/bjoc.13.221
Graphical Abstract
Figure 1: Dialkyl dicyanofumarates E-1 and dicyanomaleates Z-1.
Scheme 1: Methods for the synthesis of dialkyl dicyanofumarates E-1 from alkyl cyanoacetates 2.
Scheme 2: Methods for the synthesis of dialkyl dicyanofumarates E-1 from alkyl bromoacetates 3.
Scheme 3: Reaction of dimethyl dicyanofumarate (E-1b) with dimethoxycarbene [(MeO)2C:] generated in situ from...
Scheme 4: Cyclopropanation of diethyl dicyanofumarate (E-1a) through reaction with the thiophene derived sulf...
Scheme 5: Cyclopropanation of dimethyl dicyanofumarate (E-1b) through a stepwise reaction with the in situ ge...
Scheme 6: The [2 + 2]-cycloadditions of dimethyl dicyanofumarate (E-1b) with electron-rich ethylenes 20 and 22...
Scheme 7: The [2 + 2]-cycloaddition of isomeric dimethyl dicyanofumarate (E-1b) and dicyanomaleate (Z-1b) wit...
Scheme 8: Non-concerted [2 + 2]-cycloaddition between E-1b and bicyclo[2.1.0]pentene (27).
Scheme 9: Stepwise [3 + 2]-cycloadditions of some thiocarbonyl S-methanides with dialkyl dicyanofumarates E-1...
Scheme 10: Stepwise [3 + 2]-cycloadditions of dimethyl dicyanofumarate (E-1b) and dimethyl dicyanomaleate (Z-1b...
Scheme 11: [3 + 2]-Cycloaddition of diazomethane with dimethyl dicyanofumarate (E-1b) leading to 1H-pyrazole d...
Scheme 12: Reversible Diels–Alder reaction of fulvenes 36 with diethyl dicyanofumarate (E-1a).
Scheme 13: [4 + 2]-Cycloaddition of 9,10-dimethylanthracene (39b) and E-1a.
Scheme 14: Stepwise [4 + 2]-cycloaddition of dimethyl dicyanofumarate (E-1b) with electron-rich 1,1-dimethoxy-...
Scheme 15: Formal [4 + 2]-cycloaddition of 3,4-di(α-styryl)furan (47) with dimethyl dicyanofumarate (E-1b).
Scheme 16: Acid-catalyzed Michael addition of enolizable ketones of type 49 to E-1.
Scheme 17: Reaction of diethyl dicyanofumarate (E-1a) with ammonia NH3.
Scheme 18: Reaction of dialkyl dicyanofumarates E-1 with primary and secondary amines.
Scheme 19: Reaction of dialkyl dicyanofumarates E-1 with 1-azabicyclo[1.1.0]butanes 55.
Scheme 20: Formation of pyrazole derivatives in the reaction of hydrazines with E-1.
Scheme 21: Formation of 5-aminopyrazole-3,4-dicarboxylate 65 via heterocyclization reactions.
Scheme 22: Reactions of aryl- and hetarylcarbohydrazides 67 with E-1a.
Scheme 23: Multistep reaction leading to perhydroquinoxaline derivative 73.
Scheme 24: Synthesis of ethyl 7-aminopteridin-6-carboxylates 75 via a domino reaction.
Scheme 25: Synthesis of morhpolin-2-ones 80 from E-1 and β-aminoalcohols 78 through an initial aza-Michael add...
Scheme 26: Reaction of 3-amino-5-arylpyrazoles 81 with dialkyl dicyanofumarates E-1 via competitive nucleophil...
Scheme 27: Heterocyclization reaction of thiosemicarbazone 86 with E-1a.
Scheme 28: Formation of diethyl 4-cyano-5-oxotetrahydro-4H-chromene-3,4-dicarboxylate (90) from E-1a via heter...
Scheme 29: Reaction of dialkyl dicyanofumarates E-1 with cysteamine (92).
Scheme 30: Formation of disulfides through reaction of thiols with E-1a.
Scheme 31: Formation of CT salts of E-1 with Mn2+ and Cr2+ metallocenes through one-electron transfer.
Scheme 32: Oxidation of diethyl dicyanofumarate (E-1a) with H2O2 to give oxirane 101.
Scheme 33: The aziridination of E-1b through nitrene addition.
Beilstein J. Org. Chem. 2017, 13, 2049–2055, doi:10.3762/bjoc.13.202
Graphical Abstract
Scheme 1: TEMPO-catalysed aerobic oxidative procedures of alcohols. a) Anelli–Montanari protocol: NaOCl (1.25...
Scheme 2: TEMPO-assisted oxidation of 4-nitrobenzylic alcohol under mechanical activation conditions [65].
Scheme 3: Scope of primary alcohols in oxidation under ambient air.
Scheme 4: Scope of secondary alcohols in oxidation under ambient air.
Beilstein J. Org. Chem. 2017, 13, 675–693, doi:10.3762/bjoc.13.67
Graphical Abstract
Scheme 1: Microwave-driven reaction of glucose in the presence of PEG-200 to afford blue-emissive CDs.
Scheme 2: Two-step synthesis of TTDDA-coated CDs generated from acid-refluxed glucose.
Scheme 3: Glucose-derived CDs using KH2PO4 as a dehydrating agent to both form and tune CD’s properties.
Scheme 4: Ultrasonic-mediated synthesis of glucose-derived CDs in the presence of ammonia.
Scheme 5: Tryptophan-derived CDs used for the sensing of peroxynitrite in serum-fortified cell media.
Scheme 6: Glucose-derived CDs conjugated with methotrexate for the treatment of H157 lung cancer cells.
Scheme 7: Boron-doped blue-emissive CDs used for sensing of Fe3+ ion in solution.
Scheme 8: N/S-doped CDs with aggregation-induced fluorescence turn-off to temperature and pH stimuli.
Scheme 9: N/P-doped hollow CDs for efficient drug delivery of doxorubicin.
Scheme 10: N/P-doped CDs applied to the sensing of Fe3+ ions in mammalian T24 cells.
Scheme 11: Comparative study of CDs formed from glucose and N-doped with TTDDA and dopamine.
Scheme 12: Formation of blue-emissive CDs from the microwave irradiation of glycerol, TTDDA and phosphate.
Scheme 13: Xylitol-derived N-doped CDs with excellent photostability demonstrating the importance of Cl incorp...
Scheme 14: Base-mediated synthesis of CDs with nanocrystalline cores, from fructose and maltose, without forci...
Scheme 15: N/P-doped green-emissive CDs working in tandem with hyaluronic acid-coated AuNPs to monitor hyaluro...
Scheme 16: Three-minute microwave synthesis of Cl/N-doped CDs from glucosamine hydrochloride and TTDDA to affo...
Scheme 17: Mechanism for the formation of N/Cl-doped CDs via key aldehyde and iminium intermediates, monitored...
Scheme 18: Phosphoric acid-mediated synthesis of orange-red emissive CDs from sucrose.
Scheme 19: Proposed HMF dimer, and its formation mechanism, that upon aggregations bestows orange-red emissive...
Scheme 20: Different polysaccharide-derived CDs in the presence of PEG-200 and how the starting material compo...
Scheme 21: Tetracycline release profiles for differentially-decorated CDs.
Scheme 22: Hyaluronic acid (HA) and glycine-derived CDs, suspected to be decorated in unreacted HA, allowing r...
Scheme 23: Cyclodextrin-derived CDs used for detection of Ag+ ions in solution, based on the formal reduction ...
Scheme 24: Cyclodextrin and OEI-derived CDs, coated with hyaluronic acid and DOX, to produce an effective lung...
Scheme 25: Cellulose and urea-derived N-doped CDs with green-emissive fluorescence.
Beilstein J. Org. Chem. 2017, 13, 251–256, doi:10.3762/bjoc.13.28
Graphical Abstract
Figure 1: Retrosynthetic pathway for the synthesis of the target carbocyclic nucleoside methylphosphonates.
Scheme 1: Reagents and conditions: (a) (CH3O)2P(O)CH3, n-BuLi, THF, −78 °C/rt, 2 h, 63%; (b) H2, Pd/C, MeOH, ...
Scheme 2: Reagents and conditions: (a) N6-bis-Boc-adenine or 2-amino-6-chloropurine, PPh3, DIAD, THF, 0 °C to...
Scheme 3: Reagents and conditions: (a) N6-bis-Boc-adenine, PPh3, DIAD, THF, rt, 56%; (b) TFA, Cl(CH2)2Cl, rt,...
Figure 2: Numbering for 14 and 16.
Figure 3: Selected NOESY correlations for compound (+/−)-16.
Scheme 4: Reagents and conditions: (a) i) Boc2O, DMAP, THF, rt; ii) K2CO3, MeOH, 75%; (b) PPh3, DIAD, THF, rt...
Scheme 5: Reagents and conditions: (a) N6-Bz-adenine or 2-amino-6-chloropurine, PPh3, DIAD, THF, 0 °C to rt, ...
Beilstein J. Org. Chem. 2016, 12, 2181–2188, doi:10.3762/bjoc.12.208
Graphical Abstract
Scheme 1: Distribution of products in the Diels–Alder reaction between cyclopentadiene and p-benzoquinone.
Figure 1: Conversion in the DAR catalysed by silica Beta zeolites and Aerosil.
Figure 2: Effect of Lewis and Brønsted acid sites in the conversion (a) and selectivity (b) of the DAR.
Figure 3: Effect of pore size in the conversion (a) and selectivity (b) of the DAR.
Figure 4: Comparison of conversion (a) and selectivity (b) of the DAR catalysed by Al-Beta zeolite and MCM-41....
Figure 5: Comparison of conversion (a) and selectivity (b) of the DAR catalysed extra-large pore 3D zeolites.
Figure 6: Effect of the Si/Al ratio in the conversion (a) and selectivity (b) of the DAR.
Figure 7: Effect of the reutilization of the catalysts in the conversion (a) and selectivity (b) of the DAR.