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Search for "[4 1]-annulation" in Full Text gives 6 result(s) in Beilstein Journal of Organic Chemistry.
A facile approach to spiro[dihydrofuran-2,3'-oxindoles] via formal [4 + 1] annulation reaction of fused 1H-pyrrole-2,3-diones with diazooxindoles
- Pavel A. Topanov,
- Anna A. Maslivets,
- Maksim V. Dmitriev,
- Irina V. Mashevskaya,
- Yurii V. Shklyaev and
- Andrey N. Maslivets
Beilstein J. Org. Chem. 2022, 18, 1532–1538, doi:10.3762/bjoc.18.162
- heterocyclic systems are heteroanalogues of antimicrobial and antibiofilm fungal metabolites. The developed reaction represents the first example of involving 1H-pyrrole-2,3-diones fused at the [e]-side in a [4 + 1] annulation reaction. Keywords: [4 + 1] annulation; catalyst-free; diazooxindole; 1H-pyrrole
Graphical Abstract
Figure 1: Selected examples of biologically active natural products bearing a spirofuranoxindole moiety.
Scheme 1: Synthesis of spiro[dihydrofuran-2,3'-oxindoles] from enones and diazooxindoles.
Scheme 2: Cycloaddition reactions of [e]-fused 1H-pyrrole-2,3-diones.
Scheme 3: The model reaction of FPD 1a and diazooxindole 2a.
Scheme 4: The reaction of FPD 1k with diazooxindole 2a.
Scheme 5: A) Plausible mechanism of formal [4 + 1] cycloaddition of FPDs 1 with diazooxindoles 2 (negative ch...
Synthetic strategies for the preparation of γ-phostams: 1,2-azaphospholidine 2-oxides and 1,2-azaphospholine 2-oxides
- Jiaxi Xu
Beilstein J. Org. Chem. 2022, 18, 889–915, doi:10.3762/bjoc.18.90
- 1,2-azaphospholidine 2-oxides and their fused derivative, [4 + 1] annulations and more occasionally a [3 + 2] annulation. [4 + 1] Annulation via formations of both C–N and N–P bonds Miles and Street prepared 2-aryl/dimethylamino-1-ethoxy-2-hydrobenzo[c][1,2]azaphosphol-3-one 1-oxides 201 from 2
- proceed due to their reduced nucleophilicities, generating the corresponding phosphonamidates only through the reaction with the more electrophilic phosphonochloridate (Scheme 32) [57]. [4 + 1] Annulation via formations of both C–P and P–N bonds (1S,3R)-2-(tert-Butyldiphenylsilyl)-3-methyl-1-phenyl-2,3
- tautomerization and intramolecular aminolysis. Non-aminolysis byproduct 234 was obtained in 25% (Scheme 37). Both of the chromene-fused 5-oxo-1,2-azaphospholidine 2-oxide derivatives 233 and 234 showed good antioxidant and antitumor activities [17]. [4 + 1] Annulation via formations of both C–C and C–N bonds When
Graphical Abstract
Figure 1: Biologically active 1,2-azaphospholine 2-oxide derivatives.
Figure 2: Diverse synthetic strategies for the preparation of 1,2-azaphospholidine and 1,2-azaphospholine 2-o...
Scheme 1: Synthesis of 1-phenyl-2-phenylamino-γ-phosphonolactam (2) from N,N’-diphenyl 3-chloropropylphosphon...
Scheme 2: Synthesis of 2-ethoxy-1-methyl-γ-phosphonolactam (6) from ethyl N-methyl-(3-bromopropyl)phosphonami...
Scheme 3: Synthesis of 2-aryl-1-methyl-2,3-dihydrobenzo[c][1,2]azaphosphole 1-oxides 13 from N-aryl-2-chlorom...
Scheme 4: Synthesis of 2,3-dihydrobenzo[c][1,2]azaphosphole 1-oxides from alkylarylphosphinyl or diarylphosph...
Scheme 5: Synthesis of 3-arylmethylidene-2,3-dihydrobenzo[c][1,2]azaphosphole 1-oxides via the TBAF-mediated ...
Scheme 6: Synthesis of 2-hydrobenzo[c][1,2]azaphosphol-3-one 1-oxides via the metal-free intramolecular oxida...
Scheme 7: Synthesis of 1,3-dihydrobenzo[d][1,2]azaphosphole 2-oxides 42 and 44 from ethyl/benzyl 2-bromobenzy...
Scheme 8: Synthesis of azaphospholidine 2-oxides/sulfide from 1,2-oxaphospholane 2-oxides/sulfides and 1,2-th...
Scheme 9: Synthesis of 1,3-dihydrobenzo[d][1,2]azaphosphole 2-oxides/sulfides from 2-aminobenzyl(phenyl)phosp...
Scheme 10: Synthesis of 1,3-dihydrobenzo[d][1,2]azaphosphole 2-sulfide (59) from zwitterionic 2-aminobenzyl(ph...
Scheme 11: Synthesis of 1,3-dihydrobenzo[d][1,2]azaphosphole 2-oxides from 2-aminobenzyl(methyl/phenyl)phosphi...
Scheme 12: Synthesis of ethyl 2-methyl-1,2-azaphospholidine-5-carboxylate 2-oxide 69 from 2-amino-4-(hydroxy(m...
Scheme 13: Synthesis of 2-methoxy-1,3-dihydrobenzo[d][1,2]azaphosphole 2-oxide 71 from dimethyl 2-(methylamino...
Scheme 14: Synthesis of tricyclic γ-phosphonolactams via formation of the P–C bond.
Scheme 15: Synthesis of γ-phosphonolactams 85 from ethyl 2-(3-chloropropyl)aminoalkanoates with diethyl chloro...
Scheme 16: Synthesis of N-phosphoryl- and N-thiophosphoryl-1,2-azaphospholidine 2-oxides 90/2-sulfides 91 from...
Scheme 17: Synthesis of 1-methyl-1,3-dihydrobenzo[d][1,2]azaphosphole 2-oxides 56a and 93 from P-(chloromethyl...
Scheme 18: Synthesis of 2-allylamino-1,5-dihydro-1,2-azaphosphole 2-oxides from N,N’-diallyl-vinylphosphonodia...
Scheme 19: Diastereoselective synthesis of 2-allylamino-1,5-dihydro-1,2-azaphosphole 2-oxides from N,N’-dially...
Scheme 20: Synthesis of 1-alkyl-3-benzoyl-2-ethoxy-1,3-dihydrobenzo[d][1,2]azaphosphole 2-oxides 106 from ethy...
Scheme 21: Synthesis of cyclohexadiene-fused γ-phosphinolactams from diphenyl-N-benzyl-N-methylphosphinamide (...
Scheme 22: Synthesis of cyclohexadiene-fused γ-phosphinolactams from diphenyl-N-alkyl-N-benzylphosphinamides.
Scheme 23: Synthesis of cyclohexadiene-fused γ-phosphinolactams from diphenyl-N-methyl-N-(1-phenylethyl)phosph...
Scheme 24: Synthesis of benzocyclohexadiene-fused γ-phosphinolactams from dinaphth-1-yl-N-alkyl-N-benzylphosph...
Scheme 25: Synthesis of benzocyclohexadiene-fused γ-phosphinolactams from dinaphth-1-yl-N-benzyl-N-methylphosp...
Scheme 26: Synthesis of carbonyl-containing benzocyclohexadiene-fused γ-phosphinolactams from dinaphth-1-yl-N-...
Scheme 27: Synthesis of benzocyclohexadiene-fused γ-phosphinolactams from dinaphthyl-N-benzyl-N-methylphosphin...
Scheme 28: Synthesis of cyclohexadiene-fused 1-(N-benzyl-N-methyl)amino-γ-phosphinolactams from aryl-N,N’-dibe...
Scheme 29: Synthesis of bis(cyclohexadiene-fused γ-phosphinolactam)s from bis(diphenyl-N-benzylphosphinamide)s....
Scheme 30: Synthesis of bis(hydroxymethyl-derived cyclohexadiene-fused γ-phosphinolactam)s from tetramethylene...
Scheme 31: Synthesis of 2-aryl/dimethylamino-1-ethoxy-2-hydrobenzo[c][1,2]azaphosphol-3-one 1-oxides from ethy...
Scheme 32: Synthesis of ethyl 2-ethoxy-1,2-azaphospholidine-4-carboxylate 2-oxides from ethyl 2-((chloro(ethox...
Scheme 33: Synthesis of (1S,3R)-2-(tert-butyldiphenylsilyl)-3-methyl-1-phenyl-2,3-dihydrobenzo[c][1,2]azaphosp...
Scheme 34: Synthesis of 2,3,3a,9a-tetrahydro-4H-1,2-azaphospholo[5,4-b]chromen-4-one (215) from 3-(phenylamino...
Scheme 35: Synthesis of quinoline-fused 1,2-azaphospholine 2-oxides from 2-azidoquinoline-3-carbaldehydes and ...
Scheme 36: Synthesis of 1-hydro-1,2-azaphosphol-5-one 2-oxide from cyanoacetohydrazide with phosphonic acid an...
Scheme 37: Synthesis of chromene-fused 5-oxo-1,2-azaphospolidine 2-oxides.
Scheme 38: Synthesis of (R)-1-phenyl-2-((R)-1-phenylethyl)-2-hydrobenzo[c][1,2]azaphosphol-3-one 1-oxide (239)...
Scheme 39: Synthesis of dihydro[1,2]azaphosphole 1-oxides from aryl/vinyl-N-phenylphosphonamidates and aryl-N-...
Scheme 40: Synthesis of 1,3-dihydro-[1,2]azaphospholo[5,4-b]pyridine 2-oxides.
Rh(II)-mediated domino [4 + 1]-annulation of α-cyanothioacetamides using diazoesters: A new entry for the synthesis of multisubstituted thiophenes
- Jury J. Medvedev,
- Ilya V. Efimov,
- Yuri M. Shafran,
- Vitaliy V. Suslonov,
- Vasiliy A. Bakulev and
- Valerij A. Nikolaev
Beilstein J. Org. Chem. 2017, 13, 2569–2576, doi:10.3762/bjoc.13.253
- was also shown that α-cyanothioacetamides easily interact with dirhodium carboxylates to give rather stable 2:1 complexes, resulting in an evident decrease in the efficiency of the catalytic process at moderate temperatures (20–30 °C). Keywords: [4 + 1]-annulation; catalysis; diazo compounds; domino
Graphical Abstract
Scheme 1: General scheme for intramolecular heterocylization of intermediate X-ylides.
Figure 1: Thioamides 1a–e, diazoesters 2a–d and Rh(II)-catalysts used in the project.
Figure 2: The structures of compounds 4a and 3b according to the data of X-ray analysis (Olex2 plot with 50% ...
Scheme 2: Rh(II)-Catalyzed reactions of α-diazocyanoacetic ester 2d with α-cyanothioacetamides 1a–e.
Figure 3: The structure of thiophene 5c according to the data of X-ray analysis (Olex2 plot with 50% probabil...
Scheme 3: Interaction of thioacetamide 1e with dirhodium pivalate to produce complex 6e.
Figure 4: The structure of the complex 6e according to the data of X-ray analysis (Olex2 plot with 50% probab...
Scheme 4: The assumed mechanism for the formation of thiophenes 3, 5.
Scheme 5: The plausible mechanism for the formation of thiophenes 4.
Conjugated nitrosoalkenes as Michael acceptors in carbon–carbon bond forming reactions: a review and perspective
- Yaroslav D. Boyko,
- Valentin S. Dorokhov,
- Alexey Yu. Sukhorukov and
- Sema L. Ioffe
Beilstein J. Org. Chem. 2017, 13, 2214–2234, doi:10.3762/bjoc.13.220
- ) followed by a formal [4 + 1]-annulation reaction with ylide (tandem Michael addition/intramolecular nucleophilic substitution of dimethylsulfide by oximate anion in intermediate 94). The addition of sulfonium ylides to nitrosoalkenes can end up not only with cyclic products, but also with α,β-unsaturated
- oxidative [4 + 1]-annulation of nitrosoalkenes with 1,3-dicarbonyl compounds (Scheme 37). Optimized reaction conditions require 2 equivalents of silver carbonate as oxidizer and K2CO3 as a base to generate nitrosoalkene from a halooxime precursor 1. The plausible mechanism involves the initial conjugate
- . [4 + 1]-Annulation of nitrosoalkenes NSA with sulfonium ylides 92. Reaction of diazo compounds 96 with nitrosoalkenes NSA. Tandem Michael addition/oxidative cyclization strategy to isoxazolines 100. Acknowledgements This work was supported by Russian Foundation for Basic Research (Grants 17-03
Graphical Abstract
Scheme 1: Precursors of nitrosoalkenes NSA.
Scheme 2: Reactions of cyclic α-chlorooximes 1 with 1,3-dicarbonyl compounds.
Scheme 3: C-C-coupling of N,N-bis(silyloxy)enamines 3 with 1,3-dicarbonyl compounds.
Scheme 4: Reaction of N,N-bis(silyloxy)enamines 3 with nitronate anions.
Scheme 5: Reaction of α-chlorooximes TBS ethers 2 with ester enolates.
Scheme 6: Assembly of bicyclooctanone 14 via an intramolecular cyclization of nitrosoalkene NSA2.
Scheme 7: A general strategy for the assembly of bicyclo[2.2.1]heptanes via an intramolecular cyclization of ...
Scheme 8: Stereochemistry of Michael addition to cyclic nitrosoalkene NSA3.
Scheme 9: Stereochemistry of Michael addition to acyclic nitrosoalkenes NSA4.
Scheme 10: Stereochemistry of Michael addition to γ-alkoxy nitrosoalkene NSA5.
Scheme 11: Oppolzer’s total synthesis of 3-methoxy-9β-estra(1,3,5(10))trien(11,17)dione (25).
Scheme 12: Oppolzer’s total synthesis of (+/−)-isocomene.
Figure 1: Alkaloids synthesized using stereoselective Michael addition to conjugated nitrosoalkenes.
Scheme 13: Weinreb’s total synthesis of alstilobanines A, E and angustilodine.
Scheme 14: Weinreb’s approach to the core structure of apparicine alkaloids.
Scheme 15: Weinreb’s synthesis of (+/−)-myrioneurinol via stereoselective conjugate addition of malonate to ni...
Scheme 16: Reactions of cyclic α-chloro oximes with Grignard reagents.
Scheme 17: Corey’s synthesis of (+/−)-perhydrohistrionicotoxin.
Scheme 18: Addition of Gilman’s reagents to α,β-epoxy oximes 53.
Scheme 19: Addition of Gilman’s reagents to α-chlorooximes.
Scheme 20: Reaction of silyl nitronate 58 with organolithium reagents via nitrosoalkene NSA12.
Scheme 21: Reaction of β-ketoxime sulfones 61 and 63 with lithium acetylides.
Scheme 22: Electrophilic addition of nitrosoalkenes NSA14 to electron-rich arenes.
Scheme 23: Addition of nitrosoalkenes NSA14 to pyrroles and indoles.
Scheme 24: Reaction of phosphinyl nitrosoalkenes NSA15 with indole.
Scheme 25: Reaction of pyrrole with α,α’-dihalooximes 70.
Scheme 26: Synthesis of indole-derived psammaplin A analogue 72.
Scheme 27: Synthesis of tryptophanes by reduction of oximinoalkylated indoles 68.
Scheme 28: Ottenheijm’s synthesis of neoechinulin B analogue 77.
Scheme 29: Synthesis of 1,2-dihydropyrrolizinones 82 via addition of pyrrole to ethyl bromopyruvate oxime.
Scheme 30: Kozikowski’s strategy to indolactam-based alkaloids via addition of indoles to ethyl bromopyruvate ...
Scheme 31: Addition of cyanide anion to nitrosoalkenes and subsequent cyclization to 5-aminoisoxazoles 86.
Scheme 32: Et3N-catalysed addition of trimethylsilyl cyanide to N,N-bis(silyloxy)enamines 3 leading to 5-amino...
Scheme 33: Addition of TMSCN to allenyl N-siloxysulfonamide 89.
Scheme 34: Reaction of nitrosoallenes NSA16 with malodinitrile and ethyl cyanoacetic ester.
Scheme 35: [4 + 1]-Annulation of nitrosoalkenes NSA with sulfonium ylides 92.
Scheme 36: Reaction of diazo compounds 96 with nitrosoalkenes NSA.
Scheme 37: Tandem Michael addition/oxidative cyclization strategy to isoxazolines 100.
Synthesis of 1-indanones with a broad range of biological activity
- Marika Turek,
- Dorota Szczęsna,
- Marek Koprowski and
- Piotr Bałczewski
Beilstein J. Org. Chem. 2017, 13, 451–494, doi:10.3762/bjoc.13.48
- papilloma virus type 11 (HPV11) inhibitors. These 1-indanones 99 have been synthesized using a N-heterocyclic carbene-catalyzed [4 + 1] annulation utilizing phthalaldehyde (97) and 1,2-diactivated Michael acceptors 98 (Scheme 31) [55][56]. 1.1.5 From ketones and 1,2-diketones: Another interesting approach
Graphical Abstract
Figure 1: Biologically active 1-indanones and their structural analogues.
Figure 2: Number of papers about (a) 1-indanones, (b) synthesis of 1-indanones.
Scheme 1: Synthesis of 1-indanone (2) from hydrocinnamic acid (1).
Scheme 2: Synthesis of 1-indanone (2) from 3-(2-bromophenyl)propionic acid (3).
Scheme 3: Synthesis of 1-indanones 5 from 3-arylpropionic acids 4.
Scheme 4: Synthesis of kinamycin (9a) and methylkinamycin C (9b).
Scheme 5: Synthesis of trifluoromethyl-substituted arylpropionic acids 12, 1-indanones 13 and dihydrocoumarin...
Scheme 6: Synthesis of 1-indanones 16 from benzoic acids 15.
Scheme 7: Synthesis of 1-indanones 18 from arylpropionic and 3-arylacrylic acids 17.
Scheme 8: The NbCl5-induced one-step synthesis of 1-indanones 22.
Scheme 9: Synthesis of biologically active 1-indanone derivatives 26.
Scheme 10: Synthesis of enantiomerically pure indatraline ((−)-29).
Scheme 11: Synthesis of 1-indanone (2) from the acyl chloride 30.
Scheme 12: Synthesis of the mechanism-based inhibitors 33 of coelenterazine.
Scheme 13: Synthesis of the indane 2-imidazole derivative 37.
Scheme 14: Synthesis of fluorinated PAHs 41.
Scheme 15: Synthesis of 1-indanones 43 via transition metal complexes-catalyzed carbonylative cyclization of m...
Scheme 16: Synthesis of 6-methyl-1-indanone (46).
Scheme 17: Synthesis of 1-indanone (2) from ester 48.
Scheme 18: Synthesis of benzopyronaphthoquinone 51 from the spiro-1-indanone 50.
Scheme 19: Synthesis of the selective endothelin A receptor antagonist 55.
Scheme 20: Synthesis of 1-indanones 60 from methyl vinyl ketone (57).
Scheme 21: Synthesis of 1-indanones 64 from diethyl phthalate 61.
Scheme 22: Synthesis of 1-indanone derivatives 66 from various Meldrum’s acids 65.
Scheme 23: Synthesis of halo 1-indanones 69.
Scheme 24: Synthesis of substituted 1-indanones 71.
Scheme 25: Synthesis of spiro- and fused 1-indanones 73 and 74.
Scheme 26: Synthesis of spiro-1,3-indanodiones 77.
Scheme 27: Mechanistic pathway for the NHC-catalyzed Stetter–Aldol–Michael reaction.
Scheme 28: Synthesis of 2-benzylidene-1-indanone derivatives 88a–d.
Scheme 29: Synthesis of 1-indanone derivatives 90a–i.
Scheme 30: Synthesis of 1-indanones 96 from o-bromobenzaldehydes 93 and alkynes 94.
Scheme 31: Synthesis of 3-hydroxy-1-indanones 99.
Scheme 32: Photochemical preparation of 1-indanones 103 from ketones 100.
Scheme 33: Synthesis of chiral 3-aryl-1-indanones 107.
Scheme 34: Photochemical isomerization of 2-methylbenzil 108.
Scheme 35: Synthesis of 2-hydroxy-1-indanones 111a–c.
Scheme 36: Synthesis of 1-indanone derivatives 113 and 114 from η6-1,2-dioxobenzocyclobutene complex 112.
Scheme 37: Synthesis of nakiterpiosin (117).
Scheme 38: Synthesis of 2-alkyl-1-indanones 120.
Scheme 39: Synthesis of fluorine-containing 1-indanone derivatives 123.
Scheme 40: Synthesis of 2-benzylidene and 2-benzyl-1-indanones 126, 127 from the chalcone 124.
Scheme 41: Synthesis of 2-bromo-6-methoxy-3-phenyl-1-indanone (130).
Scheme 42: Synthesis of combretastatin A-4-like indanones 132a–s.
Figure 3: Chemical structures of investigated dienones 133 and synthesized cyclic products 134–137.
Figure 4: Chemical structures of 1-indanones and their heteroatom analogues 138–142.
Scheme 43: Synthesis of 2-phosphorylated and 2-non-phosphorylated 1-indanones 147 and 148 from β-ketophosphona...
Scheme 44: Photochemical synthesis of 1-indanone derivatives 150, 153a, 153b.
Scheme 45: Synthesis of polysubstituted-1-indanones 155, 157.
Scheme 46: Synthesis of 1-indanones 159a–g from α-arylpropargyl alcohols 158 using RhCl(PPh3)3 as a catalyst.
Scheme 47: Synthesis of optically active 1-indanones 162 via the asymmetric Rh-catalyzed isomerization of race...
Scheme 48: Mechanism of the Rh-catalyzed isomerization of α-arylpropargyl alcohols 161 to 1-indanones 162.
Figure 5: Chemical structure of abicoviromycin (168) and its new benzo derivative 169.
Scheme 49: Synthesis of racemic benzoabicoviromycin 172.
Scheme 50: Synthesis of [14C]indene 176.
Scheme 51: Synthesis of indanone derivatives 178–180.
Scheme 52: Synthesis of racemic pterosin A 186.
Scheme 53: Synthesis of trans-2,3-disubstituted 1-indanones 189.
Scheme 54: Synthesis of 3-aryl-1-indanone derivatives 192.
Scheme 55: Synthesis of 1-indanone derivatives 194 from 3-(2-iodoaryl)propanonitriles 193.
Scheme 56: Synthesis of 1-indanones 200–204 by cyclization of aromatic nitriles.
Scheme 57: Synthesis of 1,1’-spirobi[indan-3,3’-dione] derivative 208.
Scheme 58: Total synthesis of atipamezole analogues 211.
Scheme 59: Synthesis of 3-[4-(1-piperidinoethoxy)phenyl]spiro[indene-1,1’-indan]-5,5’-diol hydrochloride 216.
Scheme 60: Synthesis of 3-arylindan-1-ones 219.
Scheme 61: Synthesis of 2-hydroxy-1-indanones 222.
Scheme 62: Synthesis of the 1-indanone 224 from the THP/MOM protected chalcone epoxide 223.
Scheme 63: Synthesis of 1-indanones 227 from γ,δ-epoxy ketones 226.
Scheme 64: Synthesis of 2-hydroxy-2-methylindanone (230).
Scheme 65: Synthesis of 1-indanone derivatives 234 from cyclopropanol derivatives 233.
Scheme 66: Synthesis of substituted 1-indanone derivatives 237.
Scheme 67: Synthesis of 7-methyl substituted 1-indanone 241 from 1,3-pentadiene (238) and 2-cyclopentenone (239...
Scheme 68: Synthesis of disubstituted 1-indanone 246 from the siloxydiene 244 and 2-cyclopentenone 239.
Scheme 69: Synthesis of 5-hydroxy-1-indanone (250) via the Diels–Alder reaction of 1,3-diene 248 with sulfoxid...
Scheme 70: Synthesis of halogenated 1-indanones 253a and 253b.
Scheme 71: Synthesis of 1-indanones 257 and 258 from 2-bromocyclopentenones 254.
Scheme 72: Synthesis of 1-indanone 261 from 2-bromo-4-acetoxy-2-cyclopenten-1-one (260) and 1,2-dihydro-4-viny...
Scheme 73: Synthesis of 1-indanone 265 from 1,2-dihydro-7-methoxy-4-vinylnaphthalene (262) and bromo-substitut...
Scheme 74: Synthesis of 1-indanone 268 from dihydro-3-vinylphenanthrene 266 and 4-acetoxy-2-cyclopenten-1-one (...
Scheme 75: Synthesis of 1-indanone 271 from phenylselenyl-substituted cyclopentenone 268.
Scheme 76: Synthesis of 1-indanone 272 from the trienone 270.
Scheme 77: Synthesis of the 1-indanone 276 from the aldehyde 273.
Scheme 78: Synthesis of 1-indanones 278 and 279.
Scheme 79: Synthesis of 1-indanone 285 from octa-1,7-diyne (282) and cyclopentenone 239.
Scheme 80: Synthesis of benz[f]indan-1-one (287) from cyclopentenone 239 and o-bis(dibromomethyl)benzene (286)....
Scheme 81: Synthesis of 3-methyl-substituted benz[f]indan-1-one 291 from o-bis(dibromomethyl)benzene (286) and...
Scheme 82: Synthesis of benz[f]indan-1-one (295) from the anthracene epidioxide 292.
Scheme 83: Synthesis of 1-indanone 299 from homophthalic anhydride 298 and cyclopentynone 297.
Scheme 84: Synthesis of cyano-substituted 1-indanone derivative 301 from 2-cyanomethylbenzaldehyde (300) and c...
Scheme 85: Synthesis of 1-indanone derivatives 303–305 from ketene dithioacetals 302.
Scheme 86: Synthesis of 1-indanones 309–316.
Scheme 87: Mechanism of the hexadehydro-Diels–Alder (HDDA) reaction.
Scheme 88: Synthesis of 1-indenone 318 and 1-indanones 320 and 321 from tetraynes 317 and 319.
Scheme 89: Synthesis of 1-indanone 320 from the triyn 319.
Scheme 90: Synthesis 1-indanone 328 from 2-methylfuran 324.
Scheme 91: Synthesis of 1-indanones 330 and 331 from furans 329.
Scheme 92: Synthesis of 1-indanone 333 from the cycloadduct 332.
Scheme 93: Synthesis of (S)-3-arylindan-1-ones 335.
Scheme 94: Synthesis of (R)-2-acetoxy-1-indanone 338.
Figure 6: Chemical structures of obtained cyclopenta[α]phenanthrenes 339.
Scheme 95: Synthesis of the benzoindanone 343 from arylacetaldehyde 340 with 1-trimethylsilyloxycyclopentene (...
Recent advances in N-heterocyclic carbene (NHC)-catalysed benzoin reactions
- Rajeev S. Menon,
- Akkattu T. Biju and
- Vijay Nair
Beilstein J. Org. Chem. 2016, 12, 444–461, doi:10.3762/bjoc.12.47
- ]. Meanwhile, the Breslow intermediate is produced from the aldehyde by the thiazolium 31-derived NHC. The union of these two reactive intermediates furnished α-amidoketones 32 in excellent yields (Scheme 18). A diastereoselective [4 + 1] annulation of phthalaldehyde with imines leading to the formation of cis
Graphical Abstract
Scheme 1: Breslow’s proposal on the mechanism of the benzoin condensation.
Scheme 2: Imidazolium carbene-catalysed homo-benzoin condensation.
Scheme 3: Homo-benzoin condensation in aqueous medium.
Scheme 4: Homobenzoin condensation catalysed by bis(benzimidazolium) salt 8.
Scheme 5: List of assorted chiral NHC-catalysts used for asymmetric homobenzoin condensation.
Scheme 6: A rigid bicyclic triazole precatalyst 15 in an efficient enantioselective benzoin reaction.
Scheme 7: Inoue’s report of cross-benzoin reactions.
Scheme 8: Cross-benzoin reactions catalysed by thiazolium salt 17.
Scheme 9: Catalyst-controlled divergence in cross-benzoin reactions.
Scheme 10: Chemoselective cross-benzoin reactions catalysed by a bulky NHC.
Scheme 11: Selective intermolecular cross-benzoin condensation reactions of aromatic and aliphatic aldehydes.
Scheme 12: Chemoselective cross-benzoin reaction of aliphatic and aromatic aldehydes.
Scheme 13: Cross-benzoin reactions of trifluoromethyl ketones developed by Enders.
Scheme 14: Cross-benzoin reactions of aldehydes and α-ketoesters.
Scheme 15: Enantioselective cross-benzoin reactions of aliphatic aldehydes and α-ketoesters.
Scheme 16: Dynamic kinetic resolution of β-halo-α-ketoesters via cross-benzoin reaction.
Scheme 17: Enantioselective benzoin reaction of aldehydes and alkynones.
Scheme 18: Aza-benzoin reaction of aldehydes and acylimines.
Scheme 19: NHC-catalysed diastereoselective synthesis of cis-2-amino 3-hydroxyindanones.
Scheme 20: Cross-aza-benzoin reactions of aldehydes with aromatic imines.
Scheme 21: Enantioselective cross aza-benzoin reaction of aliphatic aldehydes with N-Boc-imines.
Scheme 22: Chemoselective cross aza-benzoin reaction of aldehydes with N-PMP-imino esters.
Scheme 23: NHC-catalysed coupling reaction of acylsilanes with imines.
Scheme 24: Thiazolium salt-mediated enantioselective cross-aza-benzoin reaction.
Scheme 25: Aza-benzoin reaction of enals with activated ketimines.
Scheme 26: Isatin derived ketimines as electrophiles in cross aza-benzoin reaction with enals.
Scheme 27: Aza-benzoin reaction of aldehydes and phosphinoylimines catalysed by the BAC-carbene.
Scheme 28: Nitrosoarenes as the electrophilic component in benzoin-initiated cascade reaction.
Scheme 29: One-pot synthesis of hydroxamic esters via aza-benzoin reaction.
Scheme 30: Cookson and Lane’s report of intramolecular benzoin condensation.
Scheme 31: Intramolecular cross-benzoin condensation between aldehyde and ketone moieties.
Scheme 32: Intramolecular crossed aldehyde-ketone benzoin reactions.
Scheme 33: Enantioselective intramolecular crossed aldehyde-ketone benzoin reaction.
Scheme 34: Chromanone synthesis via enantioselective intramolecular cross-benzoin reaction.
Scheme 35: Intramolecular cross-benzoin reaction of chalcones.
Scheme 36: Synthesis of bicyclic tertiary alcohols by intramolecular benzoin reaction.
Scheme 37: A multicatalytic Michael–benzoin cascade process for cyclopentanone synthesis.
Scheme 38: Enamine-NHC dual-catalytic, Michael–benzoin cascade reaction.
Scheme 39: Iminium-cross-benzoin cascade reaction of enals and β-oxo sulfones.
Scheme 40: Intramolecular benzoin condensation of carbohydrate-derived dialdehydes.
Scheme 41: Enantioselective intramolecular benzoin reactions of N-tethered keto-aldehydes.
Scheme 42: Asymmetric cross-benzoin reactions promoted by camphor-derived catalysts.
Scheme 43: NHC-Brønsted base co-catalysis in a benzoin–Michael–Michael cascade.
Scheme 44: Divergent catalytic dimerization of 2-formylcinnamates.
Scheme 45: One-pot, multicatalytic asymmetric synthesis of tetrahydrocarbazole derivatives.
Scheme 46: NHC-chiral secondary amine co-catalysis for the synthesis of complex spirocyclic scaffolds.
