Search for "ruthenium" in Full Text gives 271 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Beilstein J. Org. Chem. 2019, 15, 2213–2270, doi:10.3762/bjoc.15.218
Graphical Abstract
Scheme 1: The main three strategies of fluorination: nucleophilic, electrophilic and radical fluorination.
Scheme 2: Doyle’s Pd-catalyzed fluorination of allylic chlorides.
Scheme 3: Allylic fluorination of 2- and 3-substituted propenyl esters.
Scheme 4: Regioselective allylic fluorination of cinnamyl phosphorothioate esters.
Scheme 5: Palladium-catalyzed aliphatic C–H fluorination reported by Doyle.
Scheme 6: Pd-catalyzed enantioselective fluorination of α-ketoesters followed by stereoselective reduction to...
Scheme 7: Pd-catalyzed C(sp3)–H fluorination of oxindoles.
Scheme 8: C–H fluorination of 8-methylquinoline derivatives with F− reagents.
Scheme 9: Fluorination of α-cyano acetates reported by van Leeuwen.
Scheme 10: The catalytic enantioselective electrophilic C–H fluorination of α-chloro-β-keto phosphonates.
Scheme 11: Fluorination of unactivated C(sp3)–H bonds directed by the bidentate PIP auxiliary.
Scheme 12: Fluorination of C(sp3)–H bonds at the β-position of carboxylic acids.
Scheme 13: Enantioselective benzylic C–H fluorination with a chiral transient directing group.
Scheme 14: Microwave-heated Pd-catalyzed fluorination of aryl alcohols.
Scheme 15: Fluorination of aryl potassium trifluoroborates.
Scheme 16: C(sp2)–F bond formation using precatalyst [L·Pd]2(cod).
Scheme 17: Pd-catalyzed fluorination of (hetero)aryl triflates and bromides.
Scheme 18: The Pd-catalyzed C–H fluorination of arenes with Selectfluor/NFSI.
Scheme 19: Pd(II)-catalyzed ortho-monofluorination protocol for benzoic acids.
Scheme 20: Pd-catalyzed C(sp2)–H bond fluorination of 2-arylbenzothiazoles.
Scheme 21: Nitrate-promoted fluorination of aromatic and olefinic C(sp2)–H bonds and proposed mechanism.
Scheme 22: Fluorination of oxalyl amide-protected benzylamine derivatives.
Scheme 23: C–H fluorination of benzaldehydes with orthanilic acids as transient directing group.
Scheme 24: Pd(II)-catalyzed aryl C–H fluorination with various directing groups.
Scheme 25: Cu-catalyzed aliphatic, allylic, and benzylic fluorination.
Scheme 26: Cu-catalyzed SN2 fluorination of primary and secondary alkyl bromides.
Scheme 27: Copper-catalyzed fluorination of alkyl triflates.
Scheme 28: Cu-catalyzed fluorination of allylic bromides and chlorides.
Scheme 29: Synthetic strategy for the fluorination of active methylene compounds.
Scheme 30: Fluorination of β-ketoesters using a tartrate-derived bidentate bisoxazoline-Cu(II) complex.
Scheme 31: Highly enantioselective fluorination of β-ketoesters and N-Boc-oxindoles.
Scheme 32: Amide group-assisted site-selective fluorination of α-bromocarbonyl compounds.
Scheme 33: Cu-mediated aryl fluorination reported by Sanford [77].
Scheme 34: Mono- or difluorination reactions of benzoic acid derivatives.
Scheme 35: Cu-catalyzed fluorination of diaryliodonium salts with KF.
Scheme 36: Copper(I)-catalyzed cross-coupling of 2-pyridylaryl bromides.
Scheme 37: AgNO3-catalyzed decarboxylative fluorination of aliphatic carboxylic acids.
Scheme 38: The Mn-catalyzed aliphatic and benzylic C–H fluorination.
Scheme 39: Iron(II)-promoted C–H fluorination of benzylic substrates.
Scheme 40: Ag-catalyzed fluorodecarboxylation of carboxylic acids.
Scheme 41: Vanadium-catalyzed C(sp3)–H fluorination.
Scheme 42: AgNO3-catalyzed radical deboronofluorination of alkylboronates and boronic acids.
Scheme 43: Selective heterobenzylic C–H fluorination with Selectfluor reported by Van Humbeck.
Scheme 44: Fe(II)-catalyzed site-selective fluorination guided by an alkoxyl radical.
Scheme 45: Fluorination of allylic trichloroacetimidates reported by Nguyen et al.
Scheme 46: Iridium-catalyzed fluorination of allylic carbonates with TBAF(t-BuOH)4.
Scheme 47: Iridium-catalyzed asymmetric fluorination of allylic trichloroacetimidates.
Scheme 48: Cobalt-catalyzed α-fluorination of β-ketoesters.
Scheme 49: Nickel-catalyzed α-fluorination of various α-chloro-β-ketoesters.
Scheme 50: Ni(II)-catalyzed enantioselective fluorination of oxindoles and β-ketoesters.
Scheme 51: Scandium(III)-catalyzed asymmetric C–H fluorination of unprotected 3-substituted oxindoles.
Scheme 52: Iron-catalyzed directed C–H fluorination.
Scheme 53: Electrophilic silver-catalyzed Ar–F bond-forming reaction from arylstannanes.
Figure 1: Nucleophilic, electrophilic and radical CF3 sources.
Scheme 54: Cu(I)-catalyzed allylic trifluoromethylation of unactivated terminal olefins.
Scheme 55: Direct copper-catalyzed trifluoromethylation of allylsilanes.
Scheme 56: Cupper-catalyzed enantioselective trifluoromethylation of five and six-membered ring β-ketoesters.
Scheme 57: Cu-catalyzed highly stereoselective trifluoromethylation of secondary propargyl sulfonates.
Scheme 58: Remote C(sp3)–H trifluoromethylation of carboxamides and sulfonamides.
Scheme 59: Trifluoromethylation of allylsilanes with photoredox catalysis.
Scheme 60: Ag-catalyzed decarboxylative trifluoromethylation of aliphatic carboxylic acids in aqueous CH3CN.
Scheme 61: Decarboxylative trifluoromethylation of aliphatic carboxylic acids via combined photoredox and copp...
Scheme 62: Palladium-catalyzed Ar–CF3 bond-forming reaction.
Scheme 63: Palladium-catalyzed trifluoromethylation of arenes with diverse heterocyclic directing groups.
Scheme 64: Pd-catalyzed trifluoromethylation of indoles as reported by Liu.
Scheme 65: Pd-catalyzed trifluoromethylation of vinyl triflates and vinyl nonaflates.
Scheme 66: Pd(II)-catalyzed ortho-trifluoromethylation of aromatic C–H bonds.
Scheme 67: Visible-light-induced Pd(OAc)2-catalyzed ortho-trifluoromethylation of acetanilides with CF3SO2Na.
Scheme 68: CuI-catalyzed trifluoromethylation of aryl- and alkenylboronic acids.
Scheme 69: Cu-catalyzed trifluoromethylation of aryl- and vinylboronic acids.
Scheme 70: Copper-catalyzed trifluoromethylation of α,β-unsaturated carboxylic acids.
Scheme 71: Formation of C(sp2)–CF3 bond catalyzed by copper(I) complex.
Scheme 72: Loh’s Cu(I)-catalyzed trifluoromethylation of enamides and electron-deficient alkenes.
Scheme 73: Copper and iron-catalyzed decarboxylative tri- and difluoromethylation.
Scheme 74: Cu-catalyzed trifluoromethylation of hydrazones developed by Bouyssi.
Scheme 75: Cu(I)-catalyzed trifluoromethylation of terminal alkenes.
Scheme 76: Cu/Ag-catalyzed decarboxylative trifluoromethylation of cinnamic acids.
Scheme 77: Copper-catalyzed direct alkenyl C–H trifluoromethylation.
Scheme 78: Copper(I/II)-catalyzed direct trifluoromethylation of styrene derivatives.
Scheme 79: Regioselective trifluoromethylation of pivalamido arenes and heteroarenes.
Scheme 80: Synthesis of trifluoromethylquinones in the presence of copper(I).
Scheme 81: Oxidative trifluoromethylation of imidazoheterocycles in ionic liquid/water.
Scheme 82: A mild and fast continuous-flow trifluoromethylation of coumarins using a CuI/CF3SO2Na/TBHP system.
Scheme 83: Copper-catalyzed oxidative trifluoromethylation of various 8-aminoquinolines.
Scheme 84: PA-directed copper-catalyzed trifluoromethylation of anilines.
Scheme 85: Trifluoromethylation of potassium vinyltrifluoroborates catalyzed by Fe(II).
Scheme 86: Alkenyl trifluoromethylation catalyzed by Ru(phen)3Cl2 as photocatalyst.
Scheme 87: Ru-catalyzed trifluoromethylation of alkenes by Akita’s group.
Scheme 88: Ir-catalyzed Cvinyl–CF3 bond formation of α,β-unsaturated carboxylic acids.
Scheme 89: Ag(I)-catalyzed denitrative trifluoromethylation of β-nitrostyrenes.
Scheme 90: Photocatalyzed direct trifluoromethylation of aryl and heteroaryl C–H bonds.
Scheme 91: Rhenium (MTO)-catalyzed direct trifluoromethylation of aromatic substrates.
Scheme 92: Trifluoromethylation of unprotected anilines under [Ir(ppy)3] catalyst.
Scheme 93: Oxidative trifluoromethylation of imidazopyridines and imidazoheterocycles.
Scheme 94: Ruthenium-catalyzed trifluoromethylation of (hetero)arenes with trifluoroacetic anhydride.
Scheme 95: Phosphovanadomolybdic acid-catalyzed direct C–H trifluoromethylation.
Scheme 96: Picolinamide-assisted ortho-trifluoromethylation of arylamines.
Scheme 97: A nickel-catalyzed C–H trifluoromethylation of free anilines.
Scheme 98: Cu-mediated trifluoromethylation of terminal alkynes reported by Qing.
Scheme 99: Huang’s C(sp)–H trifluoromethylation using Togni’s reagent.
Scheme 100: Cu-catalyzed methods for trifluoromethylation with Umemoto’s reagent.
Scheme 101: The synthesis of alkynyl-CF3 compounds in the presence of fac-[Ir(ppy)3] under visible-light irradi...
Scheme 102: Pd-catalyzed Heck reaction reported by Reutrakul.
Scheme 103: Difluoromethylation of enamides and ene-carbamates.
Scheme 104: Difluoromethylation of α,β-unsaturated carboxylic acids.
Scheme 105: Copper-catalyzed direct C(sp2)–H difluoroacetylation reported by Pannecoucke and co-workers.
Scheme 106: Difluoroalkylation of aldehyde-derived hydrazones with functionalized difluoromethyl bromides.
Scheme 107: Photoredox-catalyzed C–H difluoroalkylation of aldehyde-derived hydrazones.
Scheme 108: Synergistic ruthenium(II)-catalyzed C–H difluoromethylation reported by Ackermann.
Scheme 109: Visible-light photocatalytic decarboxylation of α,β-unsaturated carboxylic acids.
Scheme 110: Synthesis of difluorinated ketones via S-alkyl dithiocarbamates obtained from acyl chlorides and po...
Scheme 111: Synthesis of aryl and heteroaryl difluoromethylated phosphonates.
Scheme 112: Difluoroalkylation of secondary propargyl sulfonates using Cu as the catalyst.
Scheme 113: Ru(II)-mediated para-selective difluoromethylation of anilides and their derivatives.
Scheme 114: Bulky diamine ligand promoted cross-coupling of difluoroalkyl bromides.
Scheme 115: Copper-catalyzed C3–H difluoroacetylation of quinoxalinones.
Scheme 116: Copper(I) chloride-catalyzed trifluoromethylthiolation of enamines, indoles and β-ketoesters.
Scheme 117: Copper-boxmi-catalyzed asymmetric trifluoromethylthiolation of β-ketoesters.
Scheme 118: Direct Cu-catalyzed trifluoromethylthiolation of boronic acids and alkynes.
Scheme 119: Cu-catalyzed synthesis of α-trifluoromethylthio-substituted ketones.
Scheme 120: Trifluoromethylthiolation reactions promoted by diazotriflone and copper.
Scheme 121: Halide activation of N-(trifluoromethylthio)phthalimide.
Scheme 122: The visible light-promoted trifluoromethylthiolation reported by Glorius.
Scheme 123: Synthesis of α-trifluoromethylthioesters via Goossen’s approach.
Scheme 124: Photoinduced trifluoromethylthiolation of diazonium salts.
Scheme 125: Ag-mediated trifluoromethoxylation of aryl stannanes and arylboronic acids.
Scheme 126: Catalytic (hetero)aryl C–H trifluoromethoxylation under visible light.
Scheme 127: Photoinduced C–H-bond trifluromethoxylation of (hetero)arenes.
Beilstein J. Org. Chem. 2019, 15, 2161–2169, doi:10.3762/bjoc.15.213
Graphical Abstract
Scheme 1: Reaction mechanisms of Huisgen cyclization catalyzed by Cu(I) and Ru(I).
Scheme 2: Synthesis and photochromism of bisthiazolyltriazoles.
Figure 1: Absorption spectral change of triazoles 1o–3o upon irradiation of 313 nm light in MeCN at 28 °C. Li...
Scheme 3: Wavelengths of absorption maxima of the closed forms of bisthienyletenes in hexane [36].
Scheme 4: Photochromism of closely related compounds.
Figure 2: Absorption spectral change of triazoles 1c–3c during the thermal back reaction after 313-nm light i...
Scheme 5: Bond length (a) (in Å) and Mulliken bond order (b) of 1c–3c obtained by DFT calculations. Top numbe...
Scheme 6: Possible reaction mechanism of thermal ring opening of the closed forms.
Beilstein J. Org. Chem. 2019, 15, 1996–2002, doi:10.3762/bjoc.15.195
Graphical Abstract
Figure 1: Inherent chirality generated by meta-substitution – the two structures are non-superposable mirror ...
Figure 2: General approach by Albrecht for MIC directed cyclometalation via C–H activation; M = Ru(II), Ir(II...
Figure 3: Concept of cyclometalated calix[4]arene target.
Scheme 1: Synthesis of model mesoionic carbene 5.
Scheme 2: Attempted Ullmann-coupling to give monoazide 7.
Scheme 3: Synthesis of monoazidocalix[4]arene 7 under optimized conditions.
Scheme 4: Synthesis of the putative calix[4]arene mesoionic carbene ruthenium complex 13.
Figure 4: High-resolution mass spectrum (ESI+) of putative ruthenacycle calix[4]arene 13.
Beilstein J. Org. Chem. 2019, 15, 1984–1995, doi:10.3762/bjoc.15.194
Graphical Abstract
Figure 1: Structures of triptolide (1), triptonide (2), tripdiolide (3), 16-hydroxytriptolide (4), triptrioli...
Figure 2: Syntheses of triptolide.
Scheme 1: Berchtold’s synthesis of triptolide.
Scheme 2: Li’s formal synthesis of triptolide.
Scheme 3: van Tamelen’s asymmetric synthesis of triptonide and triptolide.
Scheme 4: Van Tamelen’s (method II) formal synthesis of triptolide.
Scheme 5: Sherburn’s formal synthesis of triptolide.
Scheme 6: van Tamelen’s biogenetic type total synthesis of triptolide.
Scheme 7: Yang’s total synthesis of triptolide.
Scheme 8: Key intermediates or transformations of routes J–N.
Beilstein J. Org. Chem. 2019, 15, 1722–1757, doi:10.3762/bjoc.15.168
Graphical Abstract
Figure 1: Examples of three-carbon chirons.
Figure 2: Structures of derivatives of N-(1-phenylethyl)aziridine-2-carboxylic acid 5–8.
Figure 3: Synthetic equivalency of aziridine aldehydes 6.
Scheme 1: Synthesis of N-(1-phenylethyl)aziridine-2-carboxylates 5. Reagents and conditions: a) TEA, toluene,...
Scheme 2: Absolute configuration at C2 in (2S,1'S)-5a. Reagents and conditions: a) 20% HClO4, 80 °C, 30 h the...
Scheme 3: Major synthetic strategies for a 2-ketoaziridine scaffold [R* = (R)- or (S)-1-phenylethyl; R′ = Alk...
Scheme 4: Synthesis of cyanide (2S,1'S)-13. Reagents and conditions: a) NH3, EtOH/H2O, rt, 72 h; b) Ph3P, CCl4...
Scheme 5: Synthesis of key intermediates (R)-16 and (R)-17 for (R,R)-formoterol (14) and (R)-tamsulosin (15)....
Scheme 6: Synthesis of mitotic kinesin inhibitors (2R/S,1'R)-23. Reagents and conditions: a) H2, Pd(OH)2, EtO...
Scheme 7: Synthesis of (R)-mexiletine ((R)-24). Reagents and conditions: a) TsCl, TEA, DMAP, CH2Cl2, rt, 1 h;...
Scheme 8: Synthesis of (−)-cathinone ((S)-27). Reagents and conditions: a) PhMgBr, ether, 0 °C; b) H2, 10% Pd...
Scheme 9: Synthesis of N-Boc-norpseudoephedrine ((1S,2S)-(+)-29) and N-Boc-norephedrine ((1R,2S)-29). Reagent...
Scheme 10: Synthesis of (−)-ephedrine ((1R,2S)-31). Reagents and conditions: a) TfOMe, MeCN then NaBH3CN, rt; ...
Scheme 11: Synthesis of xestoaminol C ((2S,3R)-35), 3-epi-xestoaminol C ((2S,3S)-35) and N-Boc-spisulosine ((2S...
Scheme 12: Synthesis of ʟ-tryptophanol ((S)-41). Reagents and conditions: a) CDI, MeCN, rt, 1 h then TMSI, MeC...
Scheme 13: Synthesis of ʟ-homophenylalaninol ((S)-42). Reagents and conditions: a) NaH, THF, 0 °C to −78 °C, 1...
Scheme 14: Synthesis of ᴅ-homo(4-octylphenyl)alaninol ((R)-47) and a sphingolipid analogue (R)-48. Reagents an...
Scheme 15: Synthesis of florfenicol ((1R,2S)-49). Reagents and conditions: a) (S)-1-phenylethylamine, TEA, MeO...
Scheme 16: Synthesis of natural tyroscherin ((2S,3R,6E,8R,10R)-55). Reagents and conditions: a) I(CH2)3OTIPS, t...
Scheme 17: Syntheses of (−)-hygrine (S)-61, (−)-hygroline (2S,2'S)-62 and (−)-pseudohygroline (2S,2'R)-62. Rea...
Scheme 18: Synthesis of pyrrolidine (3S,3'R)-68, a fragment of the fluoroquinolone antibiotic PF-00951966. Rea...
Scheme 19: Synthesis of sphingolipid analogues (R)-76. Reagents and conditions: a) BnBr, Mg, THF, reflux, 6 h;...
Scheme 20: Synthesis of ᴅ-threo-PDMP (1R,2R)-81. Reagents and conditions: a) TMSCl, NaI, MeCN, rt, 1 h 50 min,...
Scheme 21: Synthesis of the sphingolipid analogue SG-14 (2S,3S)-84. Reagents and conditions: a) LiAlH4, THF, 0...
Scheme 22: Synthesis of the sphingolipid analogue SG-12 (2S,3R)-88. Reagents and conditions: a) 1-(bromomethyl...
Scheme 23: Synthesis of sphingosine-1-phosphate analogues DS-SG-44 and DS-SG-45 (2S,3R)-89a and (2S,3R)-89a. R...
Scheme 24: Synthesis of N-Boc-safingol ((2S,3S)-95) and N-Boc-ᴅ-erythro-sphinganine ((2S,3R)-95). Reagents and...
Scheme 25: Synthesis of ceramide analogues (2S,3R)-96. Reagents and conditions: a) NaBH4, ZnCl2, MeOH, −78 °C,...
Scheme 26: Synthesis of orthogonally protected serinols, (S)-101 and (R)-102. Reagents and conditions: a) BnBr...
Scheme 27: Synthesis of N-acetyl-3-phenylserinol ((1R,2R)-105). Reagents and conditions: a) AcOH, CH2Cl2, refl...
Scheme 28: Synthesis of (S)-linezolid (S)-107. Reagents and conditions: a) LiAlH4, THF, 0 °C to reflux; b) Boc2...
Scheme 29: Synthesis of (2S,3S,4R)-2-aminooctadecane-1,3,4-triol (ᴅ-ribo-phytosphingosine) (2S,3S,4R)-110. Rea...
Scheme 30: Syntheses of ᴅ-phenylalanine (R)-116. Reagents and conditions: a) AcOH, CH2Cl2, reflux, 4 h; b) MsC...
Scheme 31: Synthesis of N-Boc-ᴅ-3,3-diphenylalanine ((R)-122). Reagents and conditions: a) PhMgBr, THF, −78 °C...
Scheme 32: Synthesis of ethyl N,N’-di-Boc-ʟ-2,3-diaminopropanoate ((S)-125). Reagents and conditions: a) NaN3,...
Scheme 33: Synthesis of the bicyclic amino acid (S)-(+)-127. Reagents and conditions: a) BF3·OEt2, THF, 60 °C,...
Scheme 34: Synthesis of lacosamide, (R)-2-acetamido-N-benzyl-3-methoxypropanamide (R)-130. Reagents and condit...
Scheme 35: Synthesis of N-Boc-norfuranomycin ((2S,2'R)-133). Reagents and conditions: a) H2C=CHCH2I, NaH, THF,...
Scheme 36: Synthesis of MeBmt (2S,3R,4R,6E)-139. Reagents and conditions: a) diisopropyl (S,S)-tartrate (E)-cr...
Scheme 37: Synthesis of (+)-polyoxamic acid (2S,3S,4S)-144. Reagents and conditions: a) AD-mix-α, MeSO2NH2, t-...
Scheme 38: Synthesis of the protected 3-hydroxy-ʟ-glutamic acid (2S,3R)-148. Reagents and conditions: a) LiHMD...
Scheme 39: Synthesis of (+)-isoserine (R)-152. Reagents and conditions: a) AcCl, MeCN, rt, 0.5 h then Na2CO3, ...
Scheme 40: Synthesis of (3R,4S)-N3-Boc-3,4-diaminopentanoic acid (3R,4S)-155. Reagents and conditions: a) Ph3P...
Scheme 41: Synthesis of methyl (2S,3S,4S)-4-(dimethylamino)-2,3-dihydroxy-5-methoxypentanoate (2S,3S,4S)-159. ...
Scheme 42: Syntheses of methyl (3S,4S) 4,5-di-N-Boc-amino-3-hydroxypentanoate ((3S,4S)-164), methyl (3S,4S)-4-N...
Scheme 43: Syntheses of (3R,5S)-5-(aminomethyl)-3-(4-methoxyphenyl)dihydrofuran-2(3H)-one ((3R,5S)-168). Reage...
Scheme 44: Syntheses of a series of imidazolin-2-one dipeptides 175–177 (for R' and R'' see text). Reagents an...
Scheme 45: Syntheses of (2S,3S)-N-Boc-3-hydroxy-2-hydroxymethylpyrrolidine ((2S,3S)-179). Reagents and conditi...
Scheme 46: Syntheses of enantiomers of 1,4-dideoxy-1,4-imino-ʟ- and -ᴅ-lyxitols (2S,3R,4S)-182 and (2R,3S,4R)-...
Scheme 47: Synthesis of 1,4-dideoxy-1,4-imino-ʟ-ribitol (2S,3S,4R)-182. Reagents and conditions: a) AcOH, CH2Cl...
Scheme 48: Syntheses of 1,4-dideoxy-1,4-imino-ᴅ-arabinitol (2R,3R,4R)-182 and 1,4-dideoxy-1,4-imino-ᴅ-xylitol ...
Scheme 49: Syntheses of natural 2,5-imino-2,5,6-trideoxy-ʟ-gulo-heptitol ((2S,3R,4R,5R)-184) and its C4 epimer...
Scheme 50: Syntheses of (−)-dihydropinidine ((2S,6R)-187a) (R = C3H7) and (2S,6R)-isosolenopsins (2S,6R)-187b ...
Scheme 51: Syntheses of (+)-deoxocassine ((2S,3S,6R)-190a, R = C12H25) and (+)-spectaline ((2S,3S,6R)-190b, R ...
Scheme 52: Synthesis of (−)-microgrewiapine A ((2S,3R,6S)-194a) and (+)-microcosamine A ((2S,3R,6S)-194b). Rea...
Scheme 53: Syntheses of ʟ-1-deoxynojirimycin ((2S,3S,4S,5R)-200), ʟ-1-deoxymannojirimycin ((2S,3S,4S,5S)-200) ...
Scheme 54: Syntheses of 1-deoxy-ᴅ-galacto-homonojirimycin (2R,3S,4R,5S)-211. Reagents and conditions: a) MeONH...
Scheme 55: Syntheses of 7a-epi-hyacinthacine A1 (1S,2R,3R,7aS)-220. Reagents and conditions: a) TfOTBDMS, 2,6-...
Scheme 56: Syntheses of 8-deoxyhyacinthacine A1 ((1S,2R,3R,7aR)-221). Reagents and conditions: a) H2, Pd/C, PT...
Scheme 57: Syntheses of (+)-lentiginosine ((1S,2S,8aS)-227). Reagents and conditions: a) (EtO)2P(O)CH2COOEt, L...
Scheme 58: Syntheses of 8-epi-swainsonine (1S,2R,8S,8aR)-231. Reagents and conditions: a) Ph3P=CHCOOMe, MeOH, ...
Scheme 59: Synthesis of a protected vinylpiperidine (2S,3R)-237, a key intermediate in the synthesis of (−)-sw...
Scheme 60: Synthesis of a modified carbapenem 245. Reagents and conditions: a) AcOEt, LiHMDS, THF, −78 °C, 1.5...
Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165
Graphical Abstract
Figure 1: Various drugs having IP nucleus.
Figure 2: Participation percentage of various TMs for the syntheses of IPs.
Scheme 1: CuI–NaHSO4·SiO2-catalyzed synthesis of imidazo[1,2-a]pyridines.
Scheme 2: Experimental examination of reaction conditions.
Scheme 3: One-pot tandem reaction for the synthesis of 2-haloimidazopyridines.
Scheme 4: Mechanistic scheme for the synthesis of 2-haloimidazopyridine.
Scheme 5: Copper-MOF-catalyzed three-component reaction (3-CR) for imidazo[1,2-a]pyridines.
Scheme 6: Mechanism for copper-MOF-driven synthesis.
Scheme 7: Heterogeneous synthesis via titania-supported CuCl2.
Scheme 8: Mechanism involving oxidative C–H functionalization.
Scheme 9: Heterogeneous synthesis of IPs.
Scheme 10: One-pot regiospecific synthesis of imidazo[1,2-a]pyridines.
Scheme 11: Vinyl azide as an unprecedented substrate for imidazo[1,2-a]pyridines.
Scheme 12: Radical pathway.
Scheme 13: Cu(I)-catalyzed transannulation approach for imidazo[1,5-a]pyridines.
Scheme 14: Plausible radical pathway for the synthesis of imidazo[1,5-a]pyridines.
Scheme 15: A solvent-free domino reaction for imidazo[1,2-a]pyridines.
Scheme 16: Cu-NPs-mediated synthesis of imidazo[1,2-a]pyridines.
Scheme 17: CuI-catalyzed synthesis of isoxazolylimidazo[1,2-a]pyridines.
Scheme 18: Functionalization of 4-bromo derivative via Sonogashira coupling reaction.
Scheme 19: A plausible reaction pathway.
Scheme 20: Cu(I)-catalyzed intramolecular oxidative C–H amidation reaction.
Scheme 21: One-pot synthetic reaction for imidazo[1,2-a]pyridine.
Scheme 22: Plausible reaction mechanism.
Scheme 23: Cu(OAc)2-promoted synthesis of imidazo[1,2-a]pyridines.
Scheme 24: Mechanism for aminomethylation/cycloisomerization of propiolates with imines.
Scheme 25: Three-component synthesis of imidazo[1,2-a]pyridines.
Figure 3: Scope of pyridin-2(1H)-ones and acetophenones.
Scheme 26: CuO NPS-promoted A3 coupling reaction.
Scheme 27: Cu(II)-catalyzed C–N bond formation reaction.
Scheme 28: Mechanism involving Chan–Lam/Ullmann coupling.
Scheme 29: Synthesis of formyl-substituted imidazo[1,2-a]pyridines.
Scheme 30: A tandem sp3 C–H amination reaction.
Scheme 31: Probable mechanistic approach.
Scheme 32: Dual catalytic system for imidazo[1,2-a]pyridines.
Scheme 33: Tentative mechanism.
Scheme 34: CuO/CuAl2O4/ᴅ-glucose-promoted 3-CCR.
Scheme 35: A tandem CuOx/OMS-2-based synthetic strategy.
Figure 4: Biomimetic catalytic oxidation in the presence of electron-transfer mediators (ETMs).
Scheme 36: Control experiment.
Scheme 37: Copper-catalyzed C(sp3)–H aminatin reaction.
Scheme 38: Reaction of secondary amines.
Scheme 39: Probable mechanistic pathway.
Scheme 40: Coupling reaction of α-azidoketones.
Scheme 41: Probable pathway.
Scheme 42: Probable mechanism with free energy calculations.
Scheme 43: MCR for cyanated IP synthesis.
Scheme 44: Substrate scope for the reaction.
Scheme 45: Reaction mechanism.
Scheme 46: Probable mechanistic pathway for Cu/ZnAl2O4-catalyzed reaction.
Scheme 47: Copper-catalyzed double oxidative C–H amination reaction.
Scheme 48: Application towards different coupling reactions.
Scheme 49: Reaction mechanism.
Scheme 50: Condensation–cyclization approach for the synthesis of 1,3-diarylated imidazo[1,5-a]pyridines.
Scheme 51: Optimized reaction conditions.
Scheme 52: One-pot 2-CR.
Scheme 53: One-pot 3-CR without the isolation of chalcone.
Scheme 54: Copper–Pybox-catalyzed cyclization reaction.
Scheme 55: Mechanistic pathway catalyzed by Cu–Pybox complex.
Scheme 56: Cu(II)-promoted C(sp3)-H amination reaction.
Scheme 57: Wider substrate applicability for the reaction.
Scheme 58: Plausible reaction mechanism.
Scheme 59: CuI assisted C–N cross-coupling reaction.
Scheme 60: Probable reaction mechanism involving sp3 C–H amination.
Scheme 61: One-pot MCR-catalyzed by CoFe2O4/CNT-Cu.
Scheme 62: Mechanistic pathway.
Scheme 63: Synthetic scheme for 3-nitroimidazo[1,2-a]pyridines.
Scheme 64: Plausible mechanism for CuBr-catalyzed reaction.
Scheme 65: Regioselective synthesis of halo-substituted imidazo[1,2-a]pyridines.
Scheme 66: Synthesis of 2-phenylimidazo[1,2-a]pyridines.
Scheme 67: Synthesis of diarylated compounds.
Scheme 68: CuBr2-mediated one-pot two-component oxidative coupling reaction.
Scheme 69: Decarboxylative cyclization route to synthesize 1,3-diarylimidazo[1,5-a]pyridines.
Scheme 70: Mechanistic pathway.
Scheme 71: C–H functionalization reaction of enamines to produce diversified heterocycles.
Scheme 72: A plausible mechanism.
Scheme 73: CuI-promoted aerobic oxidative cyclization reaction of ketoxime acetates and pyridines.
Scheme 74: CuI-catalyzed pathway for the formation of imidazo[1,2-a]pyridine.
Scheme 75: Mechanistic pathway.
Scheme 76: Mechanistic rationale for the synthesis of products.
Scheme 77: Copper-catalyzed synthesis of vinyloxy-IP.
Scheme 78: Regioselective product formation with propiolates.
Scheme 79: Proposed mechanism for vinyloxy-IP formation.
Scheme 80: Regioselective synthesis of 3-hetero-substituted imidazo[1,2-a]pyridines with different reaction su...
Scheme 81: Mechanistic pathway.
Scheme 82: CuI-mediated synthesis of 3-formylimidazo[1,2-a]pyridines.
Scheme 83: Radical pathway for 3-formylated IP synthesis.
Scheme 84: Pd-catalyzed urea-cyclization reaction for IPs.
Scheme 85: Pd-catalyzed one-pot-tandem amination and intramolecular amidation reaction.
Figure 5: Scope of aniline nucleophiles.
Scheme 86: Pd–Cu-catalyzed Sonogashira coupling reaction.
Scheme 87: One-pot amide coupling reaction for the synthesis of imidazo[4,5-b]pyridines.
Scheme 88: Urea cyclization reaction for the synthesis of two series of pyridines.
Scheme 89: Amidation reaction for the synthesis of imidazo[4,5-b]pyridines.
Figure 6: Amide scope.
Scheme 90: Pd NPs-catalyzed 3-component reaction for the synthesis of 2,3-diarylated IPs.
Scheme 91: Plausible mechanistic pathway for Pd NPs-catalyzed MCR.
Scheme 92: Synthesis of chromenoannulated imidazo[1,2-a]pyridines.
Scheme 93: Mechanism for the synthesis of chromeno-annulated IPs.
Scheme 94: Zinc oxide NRs-catalyzed synthesis of imidazo[1,2-a]azines/diazines.
Scheme 95: Zinc oxide-catalyzed isocyanide based GBB reaction.
Scheme 96: Reaction pathway for ZnO-catalyzed GBB reaction.
Scheme 97: Mechanistic pathway.
Scheme 98: ZnO NRs-catalyzed MCR for the synthesis of imidazo[1,2-a]azines.
Scheme 99: Ugi type GBB three-component reaction.
Scheme 100: Magnetic NPs-catalyzed synthesis of imidazo[1,2-a]pyridines.
Scheme 101: Regioselective synthesis of 2-alkoxyimidazo[1,2-a]pyridines catalyzed by Fe-SBA-15.
Scheme 102: Plausible mechanistic pathway for the synthesis of 2-alkoxyimidazopyridine.
Scheme 103: Iron-catalyzed synthetic approach.
Scheme 104: Iron-catalyzed aminooxygenation reaction.
Scheme 105: Mechanistic pathway.
Scheme 106: Rh(III)-catalyzed double C–H activation of 2-substituted imidazoles and alkynes.
Scheme 107: Plausible reaction mechanism.
Scheme 108: Rh(III)-catalyzed non-aromatic C(sp2)–H bond activation–functionalization for the synthesis of imid...
Scheme 109: Reactivity and selectivity of different substrates.
Scheme 110: Rh-catalyzed direct C–H alkynylation by Li et al.
Scheme 111: Suggested radical mechanism.
Scheme 112: Scandium(III)triflate-catalyzed one-pot reaction and its mechanism for the synthesis of benzimidazo...
Scheme 113: RuCl3-assisted Ugi-type Groebke–Blackburn condensation reaction.
Scheme 114: C-3 aroylation via Ru-catalyzed two-component reaction.
Scheme 115: Regioselective synthetic mechanism.
Scheme 116: La(III)-catalyzed one-pot GBB reaction.
Scheme 117: Mechanistic approach for the synthesis of imidazo[1,2-a]pyridines.
Scheme 118: Synthesis of imidazo[1,2-a]pyridine using LaMnO3 NPs under neat conditions.
Scheme 119: Mechanistic approach.
Scheme 120: One-pot 3-CR for regioselective synthesis of 2-alkoxy-3-arylimidazo[1,2-a]pyridines.
Scheme 121: Formation of two possible products under optimization of the catalysts.
Scheme 122: Mechanistic strategy for NiFe2O4-catalyzed reaction.
Scheme 123: Two-component reaction for synthesizing imidazodipyridiniums.
Scheme 124: Mechanistic scheme for the synthesis of imidazodipyridiniums.
Scheme 125: CuI-catalyzed arylation of imidazo[1,2-a]pyridines.
Scheme 126: Mechanism for arylation reaction.
Scheme 127: Cupric acetate-catalyzed double carbonylation approach.
Scheme 128: Radical mechanism for double carbonylation of IP.
Scheme 129: C–S bond formation reaction catalyzed by cupric acetate.
Scheme 130: Cupric acetate-catalyzed C-3 formylation approach.
Scheme 131: Control experiments for signifying the role of DMSO and oxygen.
Scheme 132: Mechanism pathway.
Scheme 133: Copper bromide-catalyzed CDC reaction.
Scheme 134: Extension of the substrate scope.
Scheme 135: Plausible radical pathway.
Scheme 136: Transannulation reaction for the synthesis of imidazo[1,5-a]pyridines.
Scheme 137: Plausible reaction pathway for denitrogenative transannulation.
Scheme 138: Cupric acetate-catalyzed C-3 carbonylation reaction.
Scheme 139: Plausible mechanism for regioselective C-3 carbonylation.
Scheme 140: Alkynylation reaction at C-2 of 3H-imidazo[4,5-b]pyridines.
Scheme 141: Two-way mechanism for C-2 alkynylation of 3H-imidazo[4,5-b]pyridines.
Scheme 142: Palladium-catalyzed SCCR approach.
Scheme 143: Palladium-catalyzed Suzuki coupling reaction.
Scheme 144: Reaction mechanism.
Scheme 145: A phosphine free palladium-catalyzed synthesis of C-3 arylated imidazopyridines.
Scheme 146: Palladium-mediated Buchwald–Hartwig cross-coupling reaction.
Figure 7: Structure of the ligands optimized.
Scheme 147: Palladium acetate-catalyzed direct arylation of imidazo[1,2-a]pyridines.
Scheme 148: Palladium acetate-catalyzed mechanistic pathway.
Scheme 149: Palladium acetate-catalyzed regioselective arylation reported by Liu and Zhan.
Scheme 150: Mechanism for selective C-3 arylation of IP.
Scheme 151: Pd(II)-catalyzed alkenylation reaction with styrenes.
Scheme 152: Pd(II)-catalyzed alkenylation reaction with acrylates.
Scheme 153: A two way mechanism.
Scheme 154: Double C–H activation reaction catalyzed by Pd(OAc)2.
Scheme 155: Probable mechanism.
Scheme 156: Palladium-catalyzed decarboxylative coupling.
Scheme 157: Mechanistic cycle for decarboxylative arylation reaction.
Scheme 158: Ligand-free approach for arylation of imidazo[1,2-a]pyridine-3-carboxylic acids.
Scheme 159: Mechanism for ligandless arylation reaction.
Scheme 160: NHC-Pd(II) complex assisted arylation reaction.
Scheme 161: C-3 arylation of imidazo[1,2-a]pyridines with aryl bromides catalyzed by Pd(OAc)2.
Scheme 162: Pd(II)-catalyzed C-3 arylations with aryl tosylates and mesylates.
Scheme 163: CDC reaction for the synthesis of imidazo[1,2-a]pyridines.
Scheme 164: Plausible reaction mechanism for Pd(OAc)2-catalyzed synthesis of imidazo[1,2-a]pyridines.
Scheme 165: Pd-catalyzed C–H amination reaction.
Scheme 166: Mechanism for C–H amination reaction.
Scheme 167: One-pot synthesis for 3,6-di- or 2,3,6-tri(hetero)arylimidazo[1,2-a]pyridines.
Scheme 168: C–H/C–H cross-coupling reaction of IPs and azoles catalyzed by Pd(II).
Scheme 169: Mechanistic cycle.
Scheme 170: Rh-catalyzed C–H arylation reaction.
Scheme 171: Mechanistic pathway for C–H arylation of imidazo[1,2-a]pyridine.
Scheme 172: Rh(III)-catalyzed double C–H activation of 2-phenylimidazo[1,2-a]pyridines and alkynes.
Scheme 173: Rh(III)-catalyzed mechanistic pathway.
Scheme 174: Rh(III)-mediated oxidative coupling reaction.
Scheme 175: Reactions showing functionalization of the product obtained by the group of Kotla.
Scheme 176: Mechanism for Rh(III)-catalyzed oxidative coupling reaction.
Scheme 177: Rh(III)-catalyzed C–H activation reaction.
Scheme 178: Mechanistic cycle.
Scheme 179: Annulation reactions of 2-arylimidazo[1,2-a]pyridines and alkynes.
Scheme 180: Two-way reaction mechanism for annulations reaction.
Scheme 181: [RuCl2(p-cymene)]2-catalyzed C–C bond formation reaction.
Scheme 182: Reported reaction mechanism.
Scheme 183: Fe(III) catalyzed C-3 formylation approach.
Scheme 184: SET mechanism-catalyzed by Fe(III).
Scheme 185: Ni(dpp)Cl2-catalyzed KTC coupling.
Scheme 186: Pd-catalyzed SM coupling.
Scheme 187: Vanadium-catalyzed coupling of IP and NMO.
Scheme 188: Mechanistic cycle.
Scheme 189: Selective C3/C5–H bond functionalizations by mono and bimetallic systems.
Scheme 190: rGO-Ni@Pd-catalyzed C–H bond arylation of imidazo[1,2-a]pyridine.
Scheme 191: Mechanistic pathway for heterogeneously catalyzed arylation reaction.
Scheme 192: Zinc triflate-catalyzed coupling reaction of substituted propargyl alcohols.
Beilstein J. Org. Chem. 2019, 15, 1552–1562, doi:10.3762/bjoc.15.158
Graphical Abstract
Scheme 1: Oxidation of alkanes with RuO4.
Scheme 2: Mechanisms for RuO4 oxidation of alkanes.
Scheme 3: Oxidation of saturated five-membered (hetero)cyclic compounds.
Scheme 4: Rate-limiting step for the oxidation of cyclopentane (R1), tetrahydrofuran (R2) and tetrahydrothiop...
Figure 1: Optimized (B3LYP-d3bj/Def2SVP/cpcm=MeCN) geometries of transition structures corresponding to the o...
Figure 2: ELF analysis for the oxidation of cyclopentane (R1). Left: evolution of the electron population alo...
Figure 3: ELF analysis for the oxidation of tetrahydrofuran (R2, A) and tetrahydrothiophene (R3, B). Left: ev...
Figure 4: ELF assignment of electrons to the Ru environment. C(Ru) corresponds to a monosynaptic core basin a...
Scheme 5: Rate-limiting step for the oxidation of N-methyl- and N-benzylpyrrolidines R4 and R5, respectively.
Figure 5: Energy profile for the oxidation of R4 and R5. Relative energies, calculated at the B3LYP-d3bj/Def2...
Figure 6: Optimized (B3LYP-d3bj/Def2SVP/cpcm=water) transition structures for the oxidation of R4 and R5.
Beilstein J. Org. Chem. 2019, 15, 1394–1406, doi:10.3762/bjoc.15.139
Graphical Abstract
Scheme 1: (a) Schematic illustration of IDA. The addition of an analyte competitor leads to switch-on or swit...
Scheme 2: (a) The chemical structure of GC5A and schematic illustration of the binding between the luminescen...
Figure 1: Direct fluorescence titrations (λex = 350 nm) of 2,6-TNS (1.0 μM) (a) and 1,8-ANS (1.0 μM) (c) with...
Figure 2: (a) Direct fluorescence titration (λex = 327 nm) of P-TPE (1.0 μM) with GC5A in HEPES buffer (10 mM...
Figure 3: (a) Direct fluorescence titration (λex = 371 nm) of TPS (1.0 μM) with GC5A in HEPES buffer (10 mM, ...
Figure 4: (a) Direct fluorescence titration (λex = 465 nm) of Ru(dcbpy)3 (1.0 μM) with GC5A. (b) Direct absor...
Beilstein J. Org. Chem. 2019, 15, 769–779, doi:10.3762/bjoc.15.73
Graphical Abstract
Figure 1: Commercially available ruthenium catalysts for metathesis reactions.
Figure 2: Retrosynthesis of the ruthenium catalysts.
Scheme 1: Efficient multigram synthesis of N,N-dialkyl-2-vinylbenzylamines 4 (R1X = Me2SO4, Et2SO4 or BnCl, s...
Scheme 2: Synthesis of N-(2-ethenylbenzyl)heterocycles 5.
Scheme 3: Synthesis of N-monoalkyl-2-vinylbenzylamine 7.
Scheme 4: Synthesis of Hoveyda–Grubbs-type catalysts 11.
Scheme 5: Synthesis of the “chloroform adduct” 9.
Figure 3: Selected X-ray data for ruthenium complexes 11a–c. All hydrogen atoms were deleted for clarity (exc...
Scheme 6: Catalytic activity of compounds 11 in the metathesis reactions.
Beilstein J. Org. Chem. 2019, 15, 610–616, doi:10.3762/bjoc.15.56
Graphical Abstract
Scheme 1: Structures of scorzodihydrostilbenes A–E (1–5) and resveratrol.
Scheme 2: Synthesis of dihydrostilbenes 8a–d by ruthenium-catalyzed addition of ketones 6 to styrenes 7. Yiel...
Scheme 3: Cleavage of benzyl protecting groups in ketones 8a and 8b. Synthesis of scorzodihydrostilbene aglyc...
Scheme 4: Synthesis of glycoside 12 and deprotected epi-scorzodihydrostilbene D (13). Yields of isolated prod...
Beilstein J. Org. Chem. 2019, 15, 490–496, doi:10.3762/bjoc.15.42
Graphical Abstract
Figure 1: Structure of most active HPA-12 isomers, originally proposed (1) and revised (2).
Scheme 1: Lipase-catalyzed trans-acylation of (±)-4 and subsequent Mitsunobu inversion. Conditions: (i) Zn/TH...
Scheme 2: Synthesis of azide 9 from (S)-4. Conditions: (i) NaH/Bu4NI/BnBr/THF/25 °C/4 h; (ii) AD-mix-β/t-BuOH...
Scheme 3: Attempted synthesis of 2 from 9. Conditions: (i) (a) LiAlH4 (1 M in THF)/THF/25 °C/3 h, (b) DCC/DMA...
Scheme 4: Actual synthesis of 2 from 9. Conditions: (i) DDQ/CH2Cl2–H2O 4:1/3 h; (ii) a) LiAlH4/THF/25 °C/3 h,...
Beilstein J. Org. Chem. 2019, 15, 445–468, doi:10.3762/bjoc.15.39
Graphical Abstract
Scheme 1: Most common metathesis reactions. Ring-opening metathesis polymerization (ROMP), acyclic diene meta...
Scheme 2: Catalytic cycle for metathesis proposed by Chauvin.
Figure 1: Some of the most representative catalysts for aqueous metathesis. a) Well-defined ruthenium catalys...
Scheme 3: First aqueous ROMP reactions catalyzed by ruthenium(III) salts.
Scheme 4: Degradation pathway of first generation Grubbs catalyst (G-I) in methanol.
Scheme 5: Synthesis of Blechert-type catalysts 19 and 20.
Figure 2: Chemical structure and components of amphiphilic molecule PTS and derivatives.
Scheme 6: RCM of selected substrates in the presence of the surfactant PTS. Conditionsa: The reaction was car...
Scheme 7: RCM reactions of substrates 31 and 33 with the encapsulated G-II catalyst.
Scheme 8: Living ROMP of norbornene derivatives 35 and 36 with phosphine-based catalysts bearing quaternary a...
Scheme 9: Synthesis of water-soluble catalysts 3 and 4 bearing quaternary ammonium tags.
Scheme 10: In situ formation of catalyst 5 bearing a quaternary ammonium group.
Scheme 11: Catalyst recycling of an ammonium-bearing catalyst.
Scheme 12: Removal of the water-soluble catalyst 12 through host–guest interaction with silica-gel-supported β...
Scheme 13: Selection of artificial metathases reported by Ward and co-workers (ArM 1 based on biotin–(strept)a...
Figure 3: In vivo metathesis with an artificial metalloenzyme based on the biotin–streptavidin technology.
Scheme 14: Artificial metathase based on covalent anchoring approach. α-Chymotrypsin interacts with catalyst 66...
Scheme 15: Assembling an artificial metathase (ArM 4) based on the small heat shock protein from M. Jannaschii...
Scheme 16: Artificial metathases based on cavity-size engineered β-barrel protein nitrobindin (NB4exp). The HG...
Scheme 17: Artificial metathase based on cutinase (ArM 8) and resulting metathesis activities.
Scheme 18: Site-specific modification of proteins via aqueous cross-metathesis. The protein structure is based...
Scheme 19: a) Allyl homocysteine (Ahc)-modified proteins as CM substrates. b) Incorporation of Ahc in the Fc p...
Scheme 20: On-DNA cross-metathesis reaction of allyl sulfide 99.
Scheme 21: Preparation of BODIPY-containing profluorescent probes 102 and 104.
Scheme 22: Metathesis-based ethylene detection in live cells.
Scheme 23: First example of stapled peptides via olefin metathesis.
Beilstein J. Org. Chem. 2019, 15, 310–332, doi:10.3762/bjoc.15.28
Graphical Abstract
Figure 1: Cubic octasilsesquioxane.
Scheme 1: Reactivity of vinylsilanes in the presence of ruthenium alkylidene complexes; a) cross metathesis, ...
Figure 2: The scope and limitations of metathesis in transformations of vinyl-substituted siloxanes and silse...
Scheme 2: Application of olefin metathesis in the synthesis and modification of POSS-based materials: a) func...
Figure 3: Olefin metathesis catalysts used in transformations of silsesquioxanes.
Figure 4: Octavinyl-substituted cubic silsesquioxane (OVS) and spherosilicate.
Scheme 3: Cross metathesis of OVS with terminal olefins (stereoselectivity as discussed in the text).
Scheme 4: Cross metathesis of OVS with substituted styrenes.
Scheme 5: Modification of OVS via CM with styrenes.
Figure 5: Vinylbiphenyl chromophore-decorated cubic silsesquioxanes.
Scheme 6: Cross metathesis of OVS with carboranylstyrene.
Scheme 7: Synthesis of octakis[2-(p-carboxyphenyl)ethyl]silsesquioxane via CM and subsequent hydrogenation.
Scheme 8: Cross metathesis of monovinyl-POSS with olefins.
Scheme 9: Cross metathesis of monovinyl-POSS with highly π-conjugated substituted styrenes.
Scheme 10: Cross metathesis of monovinylgermasilsesquioxane with styrenes.
Scheme 11: Cross metathesis of DDSQ-2SiVi with olefins.
Scheme 12: Cross metathesis of DDSQ-2SiVi with substituted styrenes.
Scheme 13: Cross metathesis of (DDSQ-2GeVi) with olefins.
Scheme 14: CM of divinyl-substituted T10 and T12 with 4-bromostyrene (selected isomers are shown).
Scheme 15: Synthesis of vinylstilbene derivatives of T10 and T12 via a sequence of CM and Heck coupling.
Scheme 16: Cross metathesis of allyl-POSS with tert-butyl acrylate and (Z)-1,4-diacetoxy-but-2-ene.
Scheme 17: Cross metathesis of allyl-POSS with olefins.
Scheme 18: Acyclic diene metathesis copolymerization of DDSQ-2SiVi with diolefins.
Scheme 19: Acyclic diene metathesis copolymerization of DDSQ-2GeVi with diolefins.
Scheme 20: Ring-opening metathesis copolymerization of norbornenylethyl-POSS with norbornene.
Scheme 21: Synthesis of a polyethylene–POSS copolymer via ring-opening metathesis copolymerization of norborne...
Scheme 22: ROMP of norbornenylethyl-POSS with 1,5-cyclooctadiene.
Scheme 23: Copolymerization of POSS-functionalized norbornene with DCPD.
Scheme 24: Copolymerization of tris(norbornenylethyl)-POSS with DCPD.
Scheme 25: Copolymerization of N-(propyl-POSS)-7-oxanorbornene-5,6-dicarboximide with 3-(trifluoromethyl)pheny...
Figure 6: Homopolymers and copolymers having POSS groups attached to the main chain via flexible spacers of d...
Scheme 26: Ring-opening metathesis copolymerization of POSS-NBE with methyltetracyclododecene.
Scheme 27: Synthesis of block copolymer via ROMP by sequential monomer addition.
Scheme 28: Synthesis of a liquid crystalline polymer with POSS core in the side chain.
Scheme 29: Sequential synthesis of copolymers of polynorbornene containing POSS and PEO pendant groups.
Scheme 30: Synthesis of rodlike POSS−bottlebrush block copolymers [54].
Scheme 31: Surface-initiated ROMP producing copolymer layers on the surface of CdSe/ZnS quantum dots.
Beilstein J. Org. Chem. 2019, 15, 285–290, doi:10.3762/bjoc.15.25
Graphical Abstract
Scheme 1: Typical syntheses of 1,2-divinylcyclopropanes and rationale hypothesis for their syntheses from cyc...
Scheme 2: Synthesis of 1,2-divinylcyclopropane 3a: Optimization studies. aIsolated yield. bDetermined by 1H N...
Scheme 3: Synthesis of 1,2-divinylcyclopropanes 3 from cyclopropenes 1 and unbiased 1,3-dienes 2: Scope. (Yie...
Scheme 4: Rh-catalyzed intramolecular cyclopropanation with dienylcyclopropene 4 (the trans/cis ratio is rela...
Scheme 5: Zn- or Rh-catalyzed reactions of cyclopropenes 1 with furan (6) and 1,4-cyclohexadiene (8) and comp...
Beilstein J. Org. Chem. 2019, 15, 236–255, doi:10.3762/bjoc.15.22
Graphical Abstract
Figure 1: Structure of L-glutamic acid.
Figure 2: 3-Hydroxy- (2), 4-hydroxy- (3) and 3,4-dihydroxyglutamic acids (4).
Figure 3: Enantiomers of 3-hydroxyglutamic acid (2).
Scheme 1: Synthesis of (2S,3R)-2 from (R)-Garner's aldehyde. Reagents and conditions: a) MeOCH=CH–CH(OTMS)=CH2...
Scheme 2: Synthesis of (2S,3R)-2 and (2S,3S)-2 from (R)-Garner’s aldehyde. Reagents and conditions: a) H2C=CH...
Scheme 3: Two-carbon homologation of the protected L-serine. Reagents and conditions: a) Fmoc-succinimide, Na2...
Scheme 4: Synthesis of di-tert-butyl ester of (2R,3S)-2 from L-serine. Reagents and conditions: a) PhSO2Cl, K2...
Scheme 5: Synthesis of (2R,3S)-2 from O-benzyl-L-serine. Reagents and conditions: a) (CF3CH2O)2P(O)CH2COOMe, ...
Scheme 6: Synthesis of (2S,3R)-2 employing a one-pot cis-olefination–conjugate addition sequence. Reagents an...
Scheme 7: Synthesis of the orthogonally protected (2S,3R)-2 from a chiral aziridine. Reagents and conditions:...
Scheme 8: Synthesis of N-Boc-protected (2S,3R)-2 from D-phenylglycine. Reagents and conditions: a) BnMgCl, et...
Scheme 9: Synthesis of (2S,3R)-2 employing ketopinic acid as chiral auxiliary. Reagents and conditions: a) Br2...
Scheme 10: Synthesis of dimethyl ester of (2S,3R)-2 employing (1S)-2-exo-methoxyethoxyapocamphane-1-carboxylic...
Scheme 11: Synthesis of N-Boc-protected dimethyl ester of (2S,3R)-2 from (S)-N-(1-phenylethyl)thioacetamide. R...
Scheme 12: Synthesis of N-Boc-protected dimethyl ester of (2S,3R)-2 via Sharpless epoxidation. Reagents and co...
Scheme 13: Synthesis of (2S,3S)-2 from the imide 51. Reagents and conditions: a) NaBH4, MeOH/CH2Cl2; b) Ac2O, ...
Scheme 14: Synthesis of (2R,3S)-2 and (2S,3S)-2 from the acetolactam 55 (PMB = p-methoxybenzyl). Reagents and ...
Scheme 15: Synthesis of (2S,3R)-2 from D-glucose. Reagents and conditions: a) NaClO2, 30% H2O2, NaH2PO4, MeCN;...
Figure 4: Enantiomers of 3-hydroxyglutamic acid (3).
Scheme 16: Synthesis of (4S)-4-hydroxy-L-glutamic acid [(2S,4S)-3] by electrophilic hydroxylation. Reagents an...
Scheme 17: Synthesis of all stereoisomers of 4-hydroxyglutamic acid (3). Reagents and conditions: a) Br2, PBr5...
Scheme 18: Synthesis of the orthogonally protected 4-hydroxyglutamic acid (2S,4S)-73. Reagents and conditions:...
Scheme 19: Synthesis of (2S,4R)-4-acetyloxyglutamic acid as a component of a dipeptide. Reagents and condition...
Scheme 20: Synthesis of N-Boc-protected dimethyl esters of (2S,4R)- and (2S,4S)-3 from (2S,4R)-4-hydroxyprolin...
Scheme 21: Synthesis of orthogonally protected (2S,4S)-3 from (2S,4R)-4-hydroxyproline. Reagents and condition...
Scheme 22: Synthesis of the protected (4R)-4-hydroxy-L-pyroglutamic acid (2S,4R)-87 by electrophilic hydroxyla...
Figure 5: Enantiomers of 3,4-dihydroxy-L-glutamic acid (4).
Scheme 23: Synthesis of (2S,3S,4R)-4 from the epoxypyrrolidinone 88. Reagents and conditions: a) MeOH, THF, KC...
Scheme 24: Synthesis of (2S,3R,4R)-4 from the orthoester 92. Reagents and conditions: a) OsO4, NMO, acetone/wa...
Scheme 25: Synthesis of (2S,3S,4S)-4 from the aziridinolactone 95. Reagents and conditions: a) BnOH, BF3·OEt2,...
Scheme 26: Synthesis of (2S,3S,4R)-4 and (2R,3S,4R)-4 from cyclic imides 106. Reagents and conditions: a) NaBH4...
Scheme 27: Synthesis of (2R,3R,4R)-4 and (2S,3R,4R)-4 from the cyclic meso-imide 110. Reagents and conditions:...
Scheme 28: Synthesis of (2S,3S,4S)-4 from the protected serinal (R)-23. Reagents and conditions: a) Ph3P=CHCOO...
Scheme 29: Synthesis of (2S,3S,4S)-4 from O-benzyl-N-Boc-D-serine. Reagents and conditions: a) ClCOOiBu, TEA, ...
Scheme 30: Synthesis of (2S,3S,4R)-127 by enantioselective conjugate addition and asymmetric dihydroxylation. ...
Figure 6: Structures of selected compounds containing hydroxyglutamic motives (in blue).
Beilstein J. Org. Chem. 2019, 15, 218–235, doi:10.3762/bjoc.15.21
Graphical Abstract
Scheme 1: Multiblock copolymer synthesis by sequential ROMP, replotted from [51].
Figure 1: The most known commercially available catalysts for olefin metathesis.
Scheme 2: Multiblock copolymer synthesis by combining ROMP and NMP, replotted from [56].
Figure 2: A highly fluorescent multiblock copolymer for bioimaging and in vivo tumor targeting [60].
Scheme 3: Multiblock copolymer synthesis by combining ROMP and click reactions replotted from [61].
Scheme 4: Multiblock copolymer synthesis by combining ADMET and other reactions, replotted from [63,64].
Scheme 5: Synthesis of multiblock bottle-brush copolymers by ROMP, replotted from [68].
Scheme 6: Sacrificial synthesis of multiblock copolymers, replotted from [70].
Scheme 7: Synthesis of supramolecular multiblock copolymers, replotted from [74].
Figure 3: The multiblock copolymer capable of post-functionalization [76].
Figure 4: Multiblock copolymers synthesized by macromolecular cross metathesis.
Scheme 8: Macromolecular cross metathesis.
Figure 5: Changes in the DSC thermograms during MCM of PBD and polyesters (left) [84] and PNB–PCOE (right) mediat...
Figure 6: The 13C NMR spectrum recorded after 8 h of the reaction between PCOE, PNB, and Gr1; the homo- and h...
Scheme 9: Elementary reactions of MCM between PNB and PCOE, replotted from [90].
Figure 7: The 1H NMR spectrum recorded after 24 h of the reaction between PCOE, PNB, and Gr1 in CDCl3. The ca...
Scheme 10: Post-modification of multiblock copolymers by hydrogenation (A) [85] and epoxidation (B) [101] of C=C double...
Figure 8: Integral distribution functions for the lamella thickness of crystallites in thermally fractionated...
Beilstein J. Org. Chem. 2019, 15, 194–209, doi:10.3762/bjoc.15.19
Graphical Abstract
Figure 1: Structures of Grubbs 1 (1) and 2 (2) precatalysts.
Scheme 1: Design concepts for ruthenium alkylidene precatalysts [3].
Figure 2: Structures of Grubbs 1-type (3) and 2-type (4) pyridinyl-alcoholato precatalysts.
Figure 3: Structures of Grubbs 2-type (5) pyridinyl-alcoholato precatalysts.
Figure 4: Structures of pyridinyl-substituted Grubbs 2-type pyridinyl-alcoholato precatalysts.
Figure 5: The influence of the reaction temperature on the (a) conversion of 1-octene, (b) formation of PMPs ...
Figure 6: The influence of the reaction temperature on the (a) conversion of 1-octene, (b) formation of PMPs ...
Figure 7: The influence of the reaction temperature on the (a) conversion of 1-octene, (b) formation of PMPs ...
Figure 8: The influence of the reaction temperature on the (a) conversion of 1-octene, (b) formation of PMPs ...
Figure 9: Geometry-optimised structures of precatalyst 9, 6 and 8.
Figure 10: An illustration of the envisaged methoxy oxygen lone pair-aromatic π-electron interaction.
Figure 11: Influence of precatalysts 6–9 and 5d on the (a) conversion of 1-octene and (b) ln([n%1-octene]) ver...
Figure 12: 1H NMR spectra of the carbene-Hα region at different time intervals of the 1-octene/7 reaction mixt...
Figure 13: 1H NMR spectra of the Hα region of the pyridine ring of the 1-octene/7 reaction mixture in toluene-d...
Scheme 2: Synthesis of pyridinyl-alcohol ligands and Grubbs 2-type pyridinyl-alcoholato complexes.
Beilstein J. Org. Chem. 2019, 15, 160–166, doi:10.3762/bjoc.15.16
Graphical Abstract
Figure 1: Structures of the Ru-based catalysts used in this study.
Beilstein J. Org. Chem. 2019, 15, 44–51, doi:10.3762/bjoc.15.4
Graphical Abstract
Scheme 1: Strategy for sequential ROMP of 1 to yield 3.
Scheme 2: ROMP of 4 and 5 in THF at 0 °C in the presence of 10 mol % of 6.
Scheme 3: Retrosynthesis of 8 from 9.
Scheme 4: Synthesis of monomer 9.
Scheme 5: Synthesis of 14 and 8 by selective olefin metathesis.
Scheme 6: Cyclopolymerization of 15 with a flexible linker.
Scheme 7: Methanolysis of unsymmetrical ladderphane 8.
Beilstein J. Org. Chem. 2018, 14, 3122–3149, doi:10.3762/bjoc.14.292
Graphical Abstract
Figure 1: Second-generation Grubbs (GII), Hoveyda (HGII), Grela (Gre-II), Blechert (Ble-II) and indenylidene-...
Figure 2: Grubbs (1a) and Hoveyda-type (1b) complexes with N-phenyl, N’-mesityl NHCs.
Figure 3: C–H insertion product 2.
Figure 4: Grubbs (3a–6a) and Hoveyda-type (3b–6b) complexes with N-fluorophenyl, N’-aryl NHCs.
Scheme 1: RCM of diethyl diallylmalonate (7).
Scheme 2: RCM of diethyl allylmethallylmalonate (9).
Scheme 3: RCM of diethyl dimethallylmalonate (11).
Scheme 4: CM of allylbenzene (13) with cis-1,4-diacetoxy-2-butene (14).
Scheme 5: ROMP of 1,5-cyclooctadiene (16).
Figure 5: Grubbs (18a–21a) and Hoveyda-type (18b–21b) catalysts bearing uNHCs with a hexafluoroisopropylalkox...
Figure 6: A Grubbs-type complex with an N-adamantyl, N’-mesityl NHC 22 and the Hoveyda-type complex with a ch...
Figure 7: Grubbs (24a and 25a) and Hoveyda-type (24b and 25b) complexes with N-alkyl, N’-mesityl NHCs.
Figure 8: Grubbs-type complexes 31–34 with N-alkyl, N’-mesityl NHCs.
Figure 9: Grubbs-type complex 35 with an N-cyclohexyl, N’-2,6-diisopropylphenyl NHC.
Figure 10: Hoveyda-type complexes with an N-alkyl, N’-mesityl (36, 37) and an N-alkyl, N’-2,6-diisopropylpheny...
Figure 11: Indenylidene-type complexes 41–43 with N-alkyl, N’-mesityl NHCs.
Figure 12: Grubbs-type complex 44 and its monopyridine derivative 45 containing a chiral uNHC.
Scheme 6: Alternating copolymerization of 46 with 47 and 48.
Figure 13: Pyridine-containing complexes 49–52 and Grubbs-type complex 53.
Figure 14: Hoveyda-type complexes 54–58 in the alternating ROMP of NBE (46) and COE (47).
Figure 15: Catalysts 59 and 60 in the tandem RO–RCM of 47.
Figure 16: Hoveyda-type complexes 61–69 with N-alkyl, N’-aryl NHCs.
Scheme 7: Ethenolysis of methyl oleate (70).
Scheme 8: AROCM of cis-5-norbornene-endo-2,3-dicarboxylic anhydride (75) with styrene.
Figure 17: Hoveyda-type catalysts 79–82 with N-tert-butyl, N’-aryl NHCs.
Scheme 9: Latent ROMP of 83 with catalyst 82.
Figure 18: Indenylidene and Hoveyda-type complexes 85–92 with N-cycloalkyl, N’-mesityl NHCs.
Scheme 10: RCM of N,N-dimethallyl-N-tosylamide (93) with catalyst 85.
Scheme 11: Self metathesis of 13 with catalyst 85.
Figure 19: Grubbs-type complexes 98–104 with N-alkyl, N’-mesityl NHCs.
Figure 20: Grubbs-type complexes 105–115 with N-alkyl, N’-mesityl ligands.
Figure 21: Complexes 116 and 117 bearing a carbohydrate-based NHC.
Figure 22: Complexes 118 and 119 bearing a hemilabile amino-tethered NHC.
Figure 23: Indenylidene-type complexes 120–126 with N-benzyl, N’-mesityl NHCs.
Scheme 12: Diastereoselective ring-rearrangement metathesis (dRRM) of cyclopentene 131.
Figure 24: Indenylidene-type complexes 134 and 135 with N-nitrobenzyl, N’-mesityl NHCs.
Figure 25: Hoveyda-type complexes 136–138 with N-benzyl, N’-mesityl NHCs.
Figure 26: Hoveyda-type complexes 139–142 with N-benzyl, N’-Dipp NHC.
Figure 27: Indenylidene (143–146) and Hoveyda-type (147) complexes with N-heteroarylmethyl, N’-mesityl NHCs.
Figure 28: Hoveyda-type complexes 148 and 149 with N-phenylpyrrole, N’-mesityl NHCs.
Figure 29: Grubbs-type complexes with N-trifluoromethyl benzimidazolidene NHCs 150–153, 155 and N-isopropyl be...
Scheme 13: Ethenolysis of ethyl oleate 156.
Scheme 14: Ethenolysis of cis-cyclooctene (47).
Figure 30: Grubbs-type C1-symmetric (164) and C2-symmetric (165) catalysts with a backbone-substituted NHC.
Figure 31: Possible syn and anti rotational isomers of catalyst 164.
Scheme 15: ARCM of substrates 166, 168 and 170.
Figure 32: Hoveyda (172) and Grubbs-type (173,174) backbone-substituted C1-symmetric NHC complexes.
Scheme 16: ARCM of 175,177 and 179 with catalyst 174.
Figure 33: Grubbs-type C1-symmetric NHC catalysts bearing N-propyl (181, 182) or N-benzyl (183, 184) groups on...
Scheme 17: ARCM of 185 and 187 promoted by 184 to form the encumbered alkenes 186 and 188.
Figure 34: N-Alkyl, N’-isopropylphenyl NHC ruthenium complexes with syn (189, 191) and anti (190, 192) phenyl ...
Figure 35: Hoveyda-type complexes 193–198 bearing N-alkyl, N’-aryl backbone-substituted NHC ligands.
Scheme 18: ARCM of 166 and 199 promoted by 192b.
Figure 36: Enantiopure catalysts 201a and 201b with syn phenyl units on the NHC backbone.
Figure 37: Backbone-monosubstituted catalysts 202–204.
Figure 38: Grubbs (205a) and Hoveyda-type (205b) backbone-monosubstituted catalysts.
Scheme 19: AROCM of 206 with allyltrimethylsilane promoted by catalyst 205a.
Beilstein J. Org. Chem. 2018, 14, 3070–3075, doi:10.3762/bjoc.14.285
Graphical Abstract
Figure 1: Some bioactive molecules containing hydroxamate functionality.
Scheme 1: Cross metathesis between a class-I alkene and N-benzyloxyacryl amide.
Beilstein J. Org. Chem. 2018, 14, 3025–3046, doi:10.3762/bjoc.14.282
Graphical Abstract
Figure 1: Typical oxidative and reductive cycle for a photoredox catalyst (PC).
Figure 2: Transitions involved in absorbing species containing π, σ and n electrons.
Figure 3: Ligand to metal charge transfer (illustrated here for a d6 metal complex).
Figure 4: Metal to ligand charge transfer (illustrated here for a d5 metal complex).
Scheme 1: Structures of additives involved in the photoredox catalytic cycles.
Figure 5: Catalytic cycles involved with iodonium salt and (A) (TMS)3SiH, (B) NVK and (C) EDB.
Scheme 2: Structures of photoredox metal-based catalysts.
Scheme 3: Photocatalytical cycle for the Ru complex.
Scheme 4: Structures of photoredox organocatalysts.
Scheme 5: Diversity of the chemical structures of photoredox organocatalysts.
Scheme 6: Structures of benchmarked monomers.
Scheme 7: Structure of the CARET additive.
Scheme 8: Photoredox catalysis mechanism of a visible light-mediated living radical polymerization. (Abbrevia...
Beilstein J. Org. Chem. 2018, 14, 2999–3010, doi:10.3762/bjoc.14.279
Graphical Abstract
Scheme 1: Synthesis of first Ru-dithiolate metathesis catalysts.
Figure 1: Most efficient Ru-dithiolate catalysts for stereoretentive olefin metathesis with Z- and E-alkenes ...
Figure 2: Selected examples of sterically or electronically modified ruthenium dithiolate complexes.
Figure 3: Model for stereoretentive metathesis proposed by Pederson and Grubbs [3].
Figure 4: Decrease in the benzylidene signal over time upon reaction with (E)-2-hexenyl acetate.
Scheme 2: Selected applications, part 1.
Scheme 3: Selected applications, part 2.
Figure 5: Catalyst loading required for different types of metathesis reactions.
Scheme 4: Proposed catalyst decomposition pathway occurring via attack of the electron-rich sulfide into meth...
Scheme 5: In situ methylene capping strategy for stereoretentive metathesis.
Scheme 6: Stereoretentive cross-metathesis with (Z)-butene (Z-25) as in situ methylene capping agent; selecte...
Scheme 7: Cross metathesis with Z- and E-trisubstituted allylic alcohols.
Scheme 8: In situ synthesis of Ru-3 and application thereof in the cross-metathesis of 12 and 50.
Figure 6: Examples of biologically active and fragrance molecules synthesized by stereoretentive metathesis.
Beilstein J. Org. Chem. 2018, 14, 2991–2998, doi:10.3762/bjoc.14.278
Graphical Abstract
Figure 1: Illustration of coumarin taxonomy.
Scheme 1: Synthesis of oxepin-2-one-annellated coumarins 13 by RCM of acrylates 12.
Scheme 2: Attempted synthesis of pyran-2-one-annellated coumarin 15d via isomerization-RCM.
Scheme 3: Synthesis of aza-annellated coumarin 21 and attempted synthesis of indole 22.
Beilstein J. Org. Chem. 2018, 14, 2956–2963, doi:10.3762/bjoc.14.275
Graphical Abstract
Scheme 1: Catalysts studied by DFT calculations.
Scheme 2: Precatalyst initiation in olefin metathesis (L = NHC ligand).
Figure 1: Topographic steric maps (plane xy) of the NHC ligands of species I for the studied SIMes–Ru complex...
Figure 2: Intermediate II for catalysts a) 1 and b) 5 (important bond lengths are given in Å).