Search for "Michael acceptor" in Full Text gives 78 result(s) in Beilstein Journal of Organic Chemistry.
Beilstein J. Org. Chem. 2016, 12, 429–443, doi:10.3762/bjoc.12.46
Graphical Abstract
Figure 1: The structural diversity of the cinchona alkaloids, along with cupreine, cupreidine, β-isoquinidine...
Scheme 1: The original 6’-OH cinchona alkaloid organocatalytic MBH process, showing how the free 6’-OH is ess...
Scheme 2: Use of β-ICPD in an aza-MBH reaction.
Scheme 3: (a) The isatin motif is a common feature for MBH processes catalyzed by β-ICPD, as demonstrated by ...
Scheme 4: (a) Chen’s asymmetric MBH reaction. Good selectivity was dependent upon the presence of (R)-BINOL (...
Scheme 5: Lu and co-workers synthesis of a spiroxindole.
Scheme 6: Kesavan and co-workers’ synthesis of spiroxindoles.
Scheme 7: Frontier’s Nazarov cyclization catalyzed by β-ICPD.
Scheme 8: The first asymmetric nitroaldol process catalyzed by a 6’-OH cinchona alkaloid.
Scheme 9: A cupreidine derived catalyst induces a dynamic kinetic asymmetric transformation.
Scheme 10: Cupreine derivative 38 has been used in an organocatalytic asymmetric Friedel–Crafts reaction.
Scheme 11: Examples of 6’-OH cinchona alkaloid catalyzed processes include: (a) Deng’s addition of dimethyl ma...
Scheme 12: A diastereodivergent sulfa-Michael addition developed by Melchiorre and co-workers.
Scheme 13: Melchiorre’s vinylogous Michael addition.
Scheme 14: Simpkins’s TKP conjugate addition reactions.
Scheme 15: Hydrocupreine catalyst HCPN-59 can be used in an asymmetric cyclopropanation.
Scheme 16: The hydrocupreine and hydrocupreidine-based catalysts HCPN-65 and HCPD-67 demonstrate the potential...
Scheme 17: Jørgensen’s oxaziridination.
Scheme 18: Zhou’s α-amination using β-ICPD.
Scheme 19: Meng’s cupreidine catalyzed α-hydroxylation.
Scheme 20: Shi’s biomimetic transamination process for the synthesis of α-amino acids.
Scheme 21: β-Isocupreidine catalyzed [4 + 2] cycloadditions.
Scheme 22: β-Isocupreidine catalyzed [2+2] cycloaddition.
Scheme 23: A domino reaction catalyst by cupreidine catalyst CPD-30.
Scheme 24: (a) Dixon’s 6’-OH cinchona alkaloid catalyzed oxidative coupling. (b) An asymmetric oxidative coupl...
Beilstein J. Org. Chem. 2016, 12, 16–21, doi:10.3762/bjoc.12.3
Graphical Abstract
Figure 1: 4H-chromene (1) and some of its biologically active derivatives.
Scheme 1: a) Preparation of 2-bromoallyl sulfones 2a,b; b) reaction of 2a with 4-chlorophenol and Cs2CO3; c) ...
Scheme 2: Base-mediated cyclization reaction of o-hydroxychalcone 7a and 2-bromoallyl sulfone 2a.
Scheme 3: Preparation of ortho-hydroxychalcones 7a–i.
Scheme 4: Synthesis of 4H-chromenes via base-mediated reactions of 7a–i and 2a,b. Reaction conditions: 7a–i (...
Scheme 5: A plausible mechanistic rationalization for the formation of 4H-chromene derivative 8aa from 7a and ...
Beilstein J. Org. Chem. 2015, 11, 2418–2434, doi:10.3762/bjoc.11.263
Graphical Abstract
Figure 1: Possible reaction pathways in conjugate additions of nucleophiles on extended Michael acceptors.
Figure 2: Early reports of conjugate addition of copper-based reagents to extended Michael acceptors.
Figure 3: First applications of copper catalyzed 1,6-ACA in total synthesis.
Scheme 1: First example of enantioselective copper-catalyzed ACA on an extended Michael acceptor.
Scheme 2: Meldrum’s acid derivatives as substrates in enantioselective ACA.
Scheme 3: Reactivity of a cyclic dienone in Cu-catalyzed ACA of diethylzinc.
Scheme 4: Efficiency of DiPPAM ligand in 1,6-ACA of dialkylzinc to cyclic dienones.
Scheme 5: Sequential 1,6/1,4-ACA reactions involving linear aryldienones.
Scheme 6: Unsymmetrical hydroxyalkyl NHC ligands in 1,6-ACA of cyclic dienones.
Scheme 7: Performance of atropoisomeric diphosphines in 1,6-ACA of Et2Zn on cyclic dienones.
Scheme 8: Selective 1,6-ACA of Grignard reagents to acyclic dienoates, application in total synthesis.
Scheme 9: Reactivity of polyenic linear thioesters towards sequential 1,6-ACA/reconjugation/1,4-ACA and produ...
Scheme 10: 1,6-Conjugate addition of trialkylaluminium with regards to cyclic dienones.
Scheme 11: Copper-catalyzed conjugate addition of trimethylaluminium onto nitro dienoates.
Scheme 12: Copper-catalyzed selective 1,4-ACA in total synthesis of erogorgiaene.
Scheme 13: 1,4-selective addition of diethylzinc onto a cyclic enynone catalyzed by a chiral NHC-based system.
Scheme 14: Cu-NHC-catalyzed 1,6-ACA of dimethylzinc onto an α,β,γ,δ-unsaturated acyl-N-methylimidazole.
Scheme 15: 1,4-Selectivity in conjugate addition on extended systems with the concomitant use of a chelating c...
Scheme 16: Cu-NHC catalyzed 1,4-ACA as the key step in the total synthesis of ent-riccardiphenol B.
Scheme 17: Cu-NHC-catalyzed 1,4-selective ACA reactions with enynones.
Scheme 18: Linear dienones as substrates in 1,4-asymmetric conjugate addition reactions of Grignard reagents c...
Scheme 19: 1,4-ACA of trimethylaluminium to a cyclic enynone catalyzed by a copper-NHC system.
Scheme 20: Generation of a sterically encumbered chiral cyclohexanone from a polyunsaturated cyclic Michael ac...
Scheme 21: Selective conversion of β,γ-unsaturated α-ketoesters in copper-catalyzed asymmetric conjugate addit...
Scheme 22: Addition of trialkylaluminium compounds to nitroenynes catalyzed by L9/CuTC.
Scheme 23: Addition of trialkylaluminium compounds to nitrodienes catalyzed by L9/CuTC.
Scheme 24: Copper catalyzed 1,8- and 1,10-ACA reactions.
Beilstein J. Org. Chem. 2015, 11, 1265–1273, doi:10.3762/bjoc.11.141
Graphical Abstract
Scheme 1: One-pot procedure for the preparation of thioesters.
Scheme 2: Reaction of benzoyl chloride, thiourea and butyl acrylate.
Scheme 3: A proposed reaction pathway.
Beilstein J. Org. Chem. 2015, 11, 1194–1219, doi:10.3762/bjoc.11.134
Graphical Abstract
Figure 1: Pharmaceutical structures targeted in early flow syntheses.
Scheme 1: Flow synthesis of 6-hydroxybuspirone (9). Inserted photograph reprinted with permission from [45]. Copy...
Figure 2: Configuration of a baffled reactor tube (left) and its schematic working principle (right).
Scheme 2: McQuade’s flow synthesis of ibuprofen (16).
Scheme 3: Jamison’s flow synthesis of ibuprofen sodium salt (17).
Scheme 4: Flow synthesis of imatinib (23).
Scheme 5: Flow synthesis of the potent 5HT1B antagonist 28.
Scheme 6: Flow synthesis of a selective δ-opioid receptor agonist 33.
Scheme 7: Flow synthesis of a casein kinase I inhibitor library (38).
Scheme 8: Flow synthesis of fluoxetine (46).
Scheme 9: Flow synthesis of artemisinin (55).
Scheme 10: Telescoped flow synthesis of artemisinin (55) and derivatives (62–64).
Scheme 11: Flow approach towards AZD6906 (65).
Scheme 12: Pilot scale flow synthesis of key intermediate 73.
Scheme 13: Semi-flow synthesis of vildagliptine (77).
Scheme 14: Pilot scale asymmetric flow hydrogenation towards 83. Inserted photograph reprinted with permission...
Figure 3: Schematic representation of the ‘tube-in-tube’ reactor.
Scheme 15: Flow synthesis of fanetizole (87) via tube-in-tube system.
Scheme 16: Flow synthesis of diphenhydramine.HCl (92).
Scheme 17: Flow synthesis of rufinamide (95).
Scheme 18: Large scale flow synthesis of rufinamide precursor 102.
Scheme 19: First stage in the flow synthesis of meclinertant (103).
Scheme 20: Completion of the flow synthesis of meclinertant (103).
Scheme 21: Flow synthesis of olanzapine (121) utilising inductive heating techniques.
Scheme 22: Flow synthesis of amitriptyline·HCl (127).
Scheme 23: Flow synthesis of E/Z-tamoxifen (132) using peristaltic pumping modules.
Figure 4: Container sized portable mini factory (photograph credit: INVITE GmbH, Leverkusen Germany).
Scheme 24: Flow synthesis of imidazo[1,2-a]pyridines 136 linked to frontal affinity chromatography (FAC).
Figure 5: Structures of zolpidem (142) and alpidem (143).
Scheme 25: Synthesis and screening loops in the discovery of new Abl kinase inhibitors.
Figure 6: Schotten–Baumann approach towards LY573636.Na (147).
Scheme 26: Pilot scale flow synthesis of LY2886721 (146).
Scheme 27: Continuous flow manufacture of alikiren hemifumarate 152.
Beilstein J. Org. Chem. 2015, 11, 678–686, doi:10.3762/bjoc.11.77
Graphical Abstract
Figure 1: A) Schematic drawing of a bifunctional anchor molecule and its immobilization on a nanoparticle (NP...
Scheme 1: Synthesis of tripodal catecholates for surface immobilization. PEG-triscatecholate 3 was synthesize...
Scheme 2: Synthesis of tripodal catecholate platforms 11 and 13 for surface functionalization.
Figure 2: Catecholates for the immobilization on ZnO NPs.
Figure 3: A) XRD pattern of ZnO NPs obtained by the colloidal suspension of Zn(acac)2. B) TEM image of pure Z...
Figure 4: A) TGA data of catecholates 3, 13 and 14 immobilized on ZnO NPs: pure ZnO NPs treated with MOPS buf...
Figure 5: A) TGA data of catecholates 3 and 14 immobilized on ZnO NPs: pure ZnO NPs treated with MOPS buffer ...
Figure 6: TEM images of ZnO NPs. A) ZnO NPs coated with monomeric PEG-catecholate 14 after washing with water...
Beilstein J. Org. Chem. 2015, 11, 530–562, doi:10.3762/bjoc.11.60
Graphical Abstract
Scheme 1: Generic mechanism for the conjugate addition reaction.
Figure 1: Methods to activate unsaturated amide/lactam systems.
Scheme 2: DCA of Grignard reagents to an L-ephedrine derived chiral α,β–unsaturated amide.
Figure 2: Chiral auxiliaries used in DCA reactions.
Scheme 3: Comparison between auxiliary 5 and the Oppolzer auxiliary in a DCA reaction.
Scheme 4: Use of Evans auxiliary in a DCA reaction.
Figure 3: Lewis acid complex of the Evans auxiliary [43].
Scheme 5: DCA reactions of α,β-unsaturated amides utilizing (S,S)-(+)-pseudoephedrine and the OTBS-derivative...
Figure 4: Proposed model accounting for the diastereoselectivity observed in the 1,4-addition of Bn2NLi to α,...
Scheme 6: An example of a tandem conjugate addition–α-alkylation reaction of an α,β-unsaturated amide utilizi...
Scheme 7: Conjugate addition to an α,β-unsaturated bicyclic lactam leading to (+)-paroxetine and (+)-femoxeti...
Scheme 8: Intramolecular conjugate addition reaction to α,β-unsaturated amide.
Scheme 9: Conjugate addition to an α,β-unsaturated pyroglutamate derivative.
Scheme 10: Cu(I)–NHC-catalyzed asymmetric silylation of α,β-unsaturated lactams and amides.
Scheme 11: Asymmetric copper-catalyzed 1,4-borylation of an α,β-unsaturated amide.
Scheme 12: Asymmetric cross-coupling 49 to phenyl chloride.
Scheme 13: Rhodium-catalyzed asymmetric 1,4-arylation of an α,β-unsaturated lactam.
Scheme 14: Rhodium-catalyzed asymmetric 1,4-arylation of an α,β-unsaturated amide.
Scheme 15: Rhodium-catalyzed asymmetric 1,4-arylation of an α,β-unsaturated amide using a chiral bicyclic dien...
Scheme 16: Synthesis of (R)-(−)-baclofen through a rhodium-catalyzed asymmetric 1,4-arylation of lactam 58.
Scheme 17: Rhodium-catalyzed asymmetric 1,4-arylation of an α,β-unsaturated amide and lactam employing organo[...
Scheme 18: Rhodium-catalyzed asymmetric 1,4-arylation of an α,β-unsaturated lactam employing benzofuran-2-ylzi...
Figure 5: Further chiral ligands that have been used in rhodium-catalyzed 1,4-additions of α,β-unsaturated am...
Scheme 19: Palladium-catalyzed asymmetric 1,4-arylation of arylsiloxanes to a α,β-unsaturated lactam.
Scheme 20: SmI2-mediated cyclization of α,β-unsaturated Weinreb amides.
Figure 6: Chiral Lewis acid complexes used in the Mukaiyama–Michael addition of α,β-unsaturated amides.
Scheme 21: Mukaiyama–Michael addition of thioester silylketene acetal to α,β-unsaturated N-alkenoyloxazolidino...
Scheme 22: Asymmetric 1,4-addition of aryl acetylides to α,β-unsaturated thioamides.
Scheme 23: Asymmetric 1,4-addition of alkyl acetylides to α,β-unsaturated thioamides.
Scheme 24: Asymmetric vinylogous conjugate additions of unsaturated butyrolactones to α,β-unsaturated thioamid...
Scheme 25: Gd-catalyzed asymmetric 1,4-cyanation of α,β-unsaturated N-acylpyrroles [205].
Scheme 26: Lewis acid-catalyzed asymmetric 1,4-cyanation of α,β-unsaturated N-acylpyrazole 107.
Scheme 27: Lewis acid mediated 1,4-addition of dibenzyl malonate to α,β-unsaturated N-acylpyrroles.
Scheme 28: Chiral Lewis acid mediated 1,4-radical addition to α,β-unsaturated N-acyloxazolidinone [224].
Scheme 29: Aza-Michael addition of O-benzylhydroxylamine to an α,β-unsaturated N-acylpyrazole.
Scheme 30: An example of the aza-Michael addition of secondary aryl amines to an α,β-unsaturated N-acyloxazoli...
Scheme 31: Aza-Michael additions of anilines to a α,β-unsaturated N-alkenoyloxazolidinone catalyzed by palladi...
Scheme 32: Aza-Michael additions of aniline to an α,β-unsaturated N-alkenoylbenzamide and N-alkenoylcarbamate ...
Scheme 33: Difference between aza-Michael addition ran using the standard protocol versus the slow addition pr...
Scheme 34: Aza-Michael additions of aryl amines salts to an α,β-unsaturated N-alkenoyloxazolidinone catalyzed ...
Scheme 35: Aza-Michael addition of N-alkenoyloxazolidiniones catalyzed by samarium diiodide [244].
Scheme 36: Asymmetric aza-Michael addition of p-anisidine to α,β-unsaturated N-alkenoyloxazolidinones catalyze...
Scheme 37: Asymmetric aza-Michael addition of O-benzylhydroxylamine to N-alkenoyloxazolidinones catalyzed by i...
Scheme 38: Asymmetric 1,4-addition of purine to an α,β-unsaturated N-alkenoylbenzamide catalyzed by (S,S)-(sal...
Scheme 39: Asymmetric 1,4-addition of phosphites to α,β-unsaturated N-acylpyrroles.
Scheme 40: Asymmetric 1,4-addition of phosphine oxides to α,β-unsaturated N-acylpyrroles.
Scheme 41: Tandem Michael-aldol reaction catalyzed by a hydrogen-bonding organocatalyst.
Scheme 42: Examples of the sulfa-Michael–aldol reaction employing α,β-unsaturated N-acylpyrazoles.
Scheme 43: Example of the sulfa-Michael addition of α,β-unsaturated N-alkenoyloxazolidinones.
Figure 7: Structure of cinchona alkaloid-based squaramide catalyst.
Scheme 44: Asymmetric intramolecular oxa-Michael addition of an α,β-unsaturated amide.
Scheme 45: Formal synthesis atorvastatin.
Beilstein J. Org. Chem. 2014, 10, 2975–2980, doi:10.3762/bjoc.10.315
Graphical Abstract
Figure 1: MBH reaction and some selected activated alkenes.
Scheme 1: Substrate scope of the MBH reaction for various isatin and acrylamide derivatives. All reactions we...
Figure 2: ORTEP diagram of 3ea (ellipsoids are drawn at 50% probability).
Scheme 2: Substrate scope of the aza-MBH reaction for various isatin derivatives. All reactions were carried ...
Beilstein J. Org. Chem. 2014, 10, 2738–2742, doi:10.3762/bjoc.10.289
Graphical Abstract
Scheme 1: Reagents and conditions: (i) 2-methyl-2-butene, t-BuOH, NaClO2 (aq), NaH2PO4 (aq), yield: 60%; (ii)...
Scheme 2: Reagents and conditions: (i) 2.4 equiv LiNBn2, dry THF, −78 °C, 6 h, then NH4Cl (aq), overall yield...
Figure 1: Structure of 10D and an ORTEP plot of its configuration.
Scheme 3: Reagents and conditions: (i) 2.4 equiv LiNBn2, dry THF, −78 °C, 6 h, then NH4Cl (aq), overall yield...
Scheme 4: Reagents and conditions: (i) 2.4 equiv lithium (R)-N-benzyl-N-α-methylbenzylamide, dry THF, −78 °C,...
Scheme 5: Reagents and conditions: (i) 0.2 equiv KOt-Bu/t-BuOH, 40 °C, 24 h, yield: 93% (7D), 91% (13); (ii) ...
Beilstein J. Org. Chem. 2014, 10, 2089–2121, doi:10.3762/bjoc.10.218
Graphical Abstract
Figure 1: Cyclic chiral phosphines based on bridged-ring skeletons.
Figure 2: Cyclic chiral phosphines based on binaphthyl skeletons.
Figure 3: Cyclic chiral phosphines based on ferrocene skeletons.
Figure 4: Cyclic chiral phosphines based on spirocyclic skeletons.
Figure 5: Cyclic chiral phosphines based on phospholane ring skeletons.
Figure 6: Acyclic chiral phosphines.
Figure 7: Multifunctional chiral phosphines based on binaphthyl skeletons.
Figure 8: Multifunctional chiral phosphines based on amino acid skeletons.
Scheme 1: Asymmetric [3 + 2] annulations of allenoates with electron-deficient olefins, catalyzed by the chir...
Scheme 2: Asymmetric [3 + 2] annulations of allenoate and enones, catalyzed by the chiral binaphthyl-based ph...
Scheme 3: Asymmetric [3 + 2] annulations of N-substituted olefins and allenoates, catalyzed by the chiral bin...
Scheme 4: Asymmetric [3 + 2] annulations of 2-aryl-1,1-dicyanoethylenes with ethyl allenoate, catalyzed by th...
Scheme 5: Asymmetric [3 + 2] annulations of 3-alkylideneindolin-2-ones with ethyl allenoate, catalyzed by the...
Scheme 6: Asymmetric [3 + 2] annulations of 2,6-diarylidenecyclohexanones with allenoates, catalyzed by the c...
Scheme 7: Asymmetric [3 + 2] annulations of allenoate with alkylidene azlactones, catalyzed by the chiral bin...
Scheme 8: Asymmetric [3 + 2] annulations of C60 with allenoates, catalyzed by the chiral phosphine B6.
Scheme 9: Asymmetric [3 + 2] annulations of α,β-unsaturated esters and ketones with an allenoate, catalyzed b...
Scheme 10: Asymmetric [3 + 2] annulations of exocyclic enones with allenoates, catalyzed by the ferrocene-modi...
Scheme 11: Asymmetric [3 + 2] annulations of enones with an allenylphosphonate, catalyzed by the ferrocene-mod...
Scheme 12: Asymmetric [3 + 2] annulations of 3-alkylidene-oxindoles with ethyl allenoate, catalyzed by the fer...
Scheme 13: Asymmetric [3 + 2] annulations of dibenzylideneacetones with ethyl allenoate, catalyzed by the ferr...
Scheme 14: Asymmetric [3 + 2] annulations of trisubstituted alkenes with ethyl allenoate, catalyzed by the fer...
Scheme 15: Asymmetric [3 + 2] annulations of 2,6-diarylidenecyclohexanones with allenoates, catalyzed by the f...
Scheme 16: Asymmetric [3 + 2] annulations of α,β-unsaturated ketones with ethyl allenoates, catalyzed by the f...
Scheme 17: Asymmetric [3 + 2] annulations of α,β-unsaturated esters with allenoates, catalyzed by the ferrocen...
Scheme 18: Asymmetric [3 + 2] annulations of alkylidene azlactones with allenoates, catalyzed by the chiral sp...
Scheme 19: Asymmetric [3 + 2] annulations of α-trimethylsilyl allenones and electron-deficient olefins, cataly...
Scheme 20: Asymmetric [3 + 2] annulations of α,β-unsaturated ketones with an allenone, catalyzed by the chiral...
Scheme 21: Asymmetric [3 + 2] annulations of cyclic enones with allenoates, catalyzed by the chiral α-amino ac...
Scheme 22: Asymmetric [3 + 2] annulations of arylidenemalononitriles and analogues with an allenoate, catalyze...
Scheme 23: Asymmetric [3 + 2] annulations of α,β-unsaturated esters with an allenoate, catalyzed by the chiral...
Scheme 24: Asymmetric [3 + 2] annulations of 3,5-dimethyl-1H-pyrazole-derived acrylamides with an allenoate, c...
Scheme 25: Asymmetric [3 + 2] annulations of maleimides with allenoates, catalyzed by the chiral phosphine H10....
Scheme 26: Asymmetric [3 + 2] annulations of α-substituted acrylates with allenoate, catalyzed by the chiral p...
Scheme 27: Asymmetric [3 + 2] annulation of an N-tosylimine with an allenoate, catalyzed by the chiral phosphi...
Scheme 28: Asymmetric [3 + 2] annulations of N-tosylimines with an allenoate, catalyzed by the chiral phosphin...
Scheme 29: Asymmetric [3 + 2] annulations of N-tosylimines with an allenoate, catalyzed by the chiral phosphin...
Scheme 30: Asymmetric [3 + 2] annulations of N-diphenylphosphinoyl aromatic imines with butynoates, catalyzed ...
Scheme 31: Asymmetric [3 + 2] annulations of N-tosylimines with allenylphosphonates, catalyzed by the chiral p...
Scheme 32: Asymmetric [3 + 2] annulation of an N-tosylimine with an allenoate, catalyzed by the chiral phosphi...
Scheme 33: Asymmetric [3 + 2] annulations of N-diphenylphosphinoyl aromatic imines with allenoates (top), cata...
Scheme 34: Asymmetric [3 + 2] annulation of N-diphenylphosphinoylimines with allenoates, catalyzed by the chir...
Scheme 35: Asymmetric [3 + 2] annulation of an azomethine imine with an allenoate, catalyzed by the chiral pho...
Scheme 36: Asymmetric [3 + 2] annulations between α,β-unsaturated esters/ketones and 3-butynoates, catalyzed b...
Scheme 37: Asymmetric intramolecular [3 + 2] annulations of electron-deficient alkenes and MBH carbonates, cat...
Scheme 38: Asymmetric [3 + 2] annulations of methyleneindolinone and methylenebenzofuranone derivatives with M...
Scheme 39: Asymmetric [3 + 2] annulations of activated isatin-based alkenes with MBH carbonates, catalyzed by ...
Scheme 40: Asymmetric [3 + 2] annulations of maleimides with MBH carbonates, catalyzed by the chiral phosphine ...
Scheme 41: A series of [3 + 2] annulations of various activated alkenes with MBH carbonates, catalyzed by the ...
Scheme 42: Asymmetric [3 + 2] annulations of an alkyne with isatins, catalyzed by the chiral phosphine F1.
Scheme 43: Asymmetric [4 + 2] annulations catalyzed by the chiral phosphine B1.
Scheme 44: Asymmetric [4 + 2] annulations catalyzed by the chiral phosphine H5.
Scheme 45: Asymmetric [4 + 2] annulations catalyzed by the chiral phosphines H13 and H12.
Scheme 46: Asymmetric [4 + 2] annulations catalyzed by the chiral phosphine H6.
Scheme 47: Kerrigan’s [2 + 2] annulations of ketenes with imines, catalyzed by the chiral phosphine B7.
Scheme 48: Asymmetric [4 + 1] annulations, catalyzed by the chiral phosphine G6.
Scheme 49: Asymmetric homodimerization of ketenes, catalyzed by the chiral phosphine F5 and F6.
Scheme 50: Aza-MBH/Michael reactions, catalyzed by the chiral phosphine G1.
Scheme 51: Tandem RC/Michael additions, catalyzed by the chiral phosphine H14.
Scheme 52: Intramolecular tandem RC/Michael addition, catalyzed by the chiral phosphine H15.
Scheme 53: Double-Michael addition, catalyzed by the chiral aminophosphine G9.
Scheme 54: Tandem Michael addition/Wittig olefinations, mediated by the chiral phosphine BIPHEP.
Scheme 55: Asymmetric Michael additions, catalyzed by the chiral phosphines H7, H8, and H9.
Scheme 56: Asymmetric γ-umpolung additions, catalyzed by the chiral phosphine A1.
Scheme 57: Asymmetric γ-umpolung additions, catalyzed by the chiral phosphines E2 and E3.
Scheme 58: Intramolecular γ-additions of hydroxy-2-alkynoates, catalyzed by the chiral phosphine D2.
Scheme 59: Intra-/intermolecular γ-additions, catalyzed by the chiral phosphine D2.
Scheme 60: Intermolecular γ-additions, catalyzed by the chiral phosphines B5 and B3.
Scheme 61: Intermolecular γ-additions, catalyzed by the chiral phosphines E6 and B4.
Scheme 62: Asymmetric allylic substitution of MBH acetates, catalyzed by the chiral phosphine G2.
Scheme 63: Allylic substitutions between MBH acetates or carbonates and an array of nucleophiles, catalyzed by...
Scheme 64: Asymmetric acylation of diols, catalyzed by the chiral phosphines E4 and E5.
Scheme 65: Kinetic resolution of secondary alcohols, catalyzed by the chiral phosphine E8 and E9.
Beilstein J. Org. Chem. 2014, 10, 1848–1877, doi:10.3762/bjoc.10.195
Graphical Abstract
Figure 1: Examples of phosphonamide reagents used in stereoselective synthesis.
Figure 2: Natural products and bioactive molecules synthesized using phosphonamide-based chemistry (atoms, bo...
Scheme 1: Olefination with cyclic phosphonamide anions, mechanistic rationale, and selected examples 27a–d [18].
Scheme 2: Asymmetric olefination with chiral phosphonamide anions and selected examples 31a–d [1,22].
Scheme 3: Synthesis of α-substituted phosphonic acids 33a–e by asymmetric alkylation of chiral phosphonamide ...
Scheme 4: Asymmetric conjugate additions of C2-symmetric chiral phosphonamide anions to cyclic enones, lacton...
Scheme 5: Asymmetric conjugate additions of P-chiral phosphonamide anions generated from 40a and 44a to cycli...
Scheme 6: Asymmetric cyclopropanation with chiral chloroallyl phosphonamide 47, mechanistic rationale, and se...
Scheme 7: Asymmetric cyclopropanation with chiral chloromethyl phosphonamide 28d [59].
Scheme 8: Stereoselective synthesis of cis-aziridines 57 from chiral chloroallyl phosphonamide 47a [62].
Scheme 9: Synthesis of phosphonamides by (A) Arbuzov reaction, (B) condensation of diamines with phosphonic a...
Figure 3: Original and revised structure of polyoxin A (69) [24-26].
Scheme 10: Synthesis of (E)-polyoximic acid (9) [24-26].
Figure 4: Key assembly strategy of acetoxycrenulide (10) [41,42].
Scheme 11: Total synthesis of (+)-acetoxycrenulide (10) [41,42].
Scheme 12: Synthesis squalene synthase inhibitor 19 by asymmetric sulfuration (A) and asymmetric alkylation (B...
Figure 5: Key assembly strategy of fumonisin B2 (20) and its tricarballylic acid fragment 105 [45,46].
Scheme 13: Final steps of the total synthesis of fumonisin B2 (20) [45,46].
Figure 6: Selected examples of two subclasses of β-lactam antibiotics – carbapenems (111 and 112) and trinems...
Scheme 14: Synthesis of tricyclic β-lactam antibiotic 123 [97].
Scheme 15: Total synthesis of (−)-anthoplalone (8) [56].
Figure 7: Protein tyrosine phosphatase (PTP) inhibitors 130, 131 and model compounds 16, 132 and 133 [68].
Scheme 16: Synthesis of model PTP inhibitors 16a,b [68].
Scheme 17: Synthesis of aziridine hydroxamic acid 17 as MMP inhibitor [63].
Scheme 18: Synthesis of methyl jasmonate (11) [48].
Figure 8: Structures of nudiflosides A (137) and D (13) [49].
Scheme 19: Total synthesis of the pentasubstituted cyclopentane core 159 of nudiflosides A (151) and D (13) an...
Figure 9: L-glutamic acid (161) and constrained analogues [57,124].
Scheme 20: Stereoselective synthesis of DCG-IV (162) [57].
Scheme 21: Stereoselective synthesis of mGluR agonist 21 [124].
Figure 10: Key assembly strategy of berkelic acid (15) [43].
Scheme 22: Total synthesis of berkelic acid (15) [43].
Figure 11: Key assembly strategy of jerangolid A (22) and ambruticin S (14) [27,28].
Scheme 23: Final assembly steps in the total synthesis of jerangolid A [27].
Scheme 24: Key assembly steps in the total synthesis of ambruticin S (14) [28].
Figure 12: General steroid construction strategy based on conjugate addition of 212 to cyclopentenone 48, exem...
Scheme 25: Total synthesis of estrone (12) [44].
Beilstein J. Org. Chem. 2014, 10, 1796–1801, doi:10.3762/bjoc.10.188
Graphical Abstract
Figure 1: TDA and related natural products from Phaeobacter inhibens.
Scheme 1: Synthesis of tropone-2-carboxylic acid (13).
Scheme 2: Synthesis of halogenated TDA analogues.
Scheme 3: Further compounds included in this SAR study.
Beilstein J. Org. Chem. 2014, 10, 1064–1096, doi:10.3762/bjoc.10.106
Graphical Abstract
Scheme 1: Synthesis of P-stereogenic phosphines 5 using menthylphosphinite borane diastereomers 2.
Scheme 2: Enantioselective synthesis of chiral phosphines 10 with ephedrine as a chiral auxiliary.
Scheme 3: Chlorophosphine boranes 11a as P-chirogenic electrophilic building blocks.
Scheme 4: Monoalkylation of phenylphosphine borane 15 with methyl iodide in the presence of Cinchona alkaloid...
Scheme 5: Preparation of tetraphosphine borane 19.
Scheme 6: Using chiral chlorophosphine-boranes 11b as phosphide borane 20 precursors.
Scheme 7: Nickel-catalyzed cross-coupling (dppe = 1,2-bis(diphenylphosphino)ethane).
Scheme 8: Pd-catalyzed cross-coupling reaction with organophosphorus stannanes 30.
Scheme 9: Copper iodide catalyzed carbon–phosphorus bond formation.
Scheme 10: Thermodynamic kinetic resolution as the origin of enantioselectivity in metal-catalyzed asymmetric ...
Scheme 11: Ru-catalyzed asymmetric phosphination of benzyl and alkyl chlorides 35 with HPPhMe (36a, PHOX = pho...
Scheme 12: Pt-catalyzed asymmetric alkylation of secondary phosphines 36b.
Scheme 13: Different adducts 43 can result from hydrophosphination.
Scheme 14: Pt-catalyzed asymmetric hydrophosphination.
Scheme 15: Intramolecular hydrophosphination of phosphinoalkene 47.
Scheme 16: Organocatalytic asymmetric hydrophosphination of α,β-unsaturated aldehydes 59.
Scheme 17: Preparation of phosphines using zinc organometallics.
Scheme 18: Preparation of alkenylphosphines 71a from alkenylzirconocenes 69 (dtc = N,N-diethyldithiocarbamate,...
Scheme 19: SNAr with P-chiral alkylmethylphosphine boranes 13c.
Scheme 20: Synthesis of QuinoxP 74 (TMEDA = tetramethylethylenediamine).
Scheme 21: Pd-Mediated couplings of a vinyl triflate 76 with diphenylphosphine borane 13e.
Figure 1: Menthone (83) and camphor (84) derived chiral phosphines.
Scheme 22: Palladium-catalyzed cross-coupling reaction of vinyl tosylates 85 and 87 with diphenylphosphine bor...
Scheme 23: Attempt for the enantioselective palladium-catalyzed C–P cross-coupling reaction between an alkenyl...
Scheme 24: Enol phosphates 88 as vinylic coupling partners in the palladium-catalyzed C–P cross-coupling react...
Scheme 25: Nickel-catalyzed cross-coupling in the presence of zinc (dppe = 1,2-bis(diphenylphosphino)ethane).
Scheme 26: Copper-catalyzed coupling of secondary phosphines with vinyl halide 94.
Scheme 27: Palladium-catalyzed cross-coupling of aryl iodides 97 with organoheteroatom stannanes 30.
Scheme 28: Synthesis of optically active phosphine boranes 100 by cross-coupling with a chiral phosphine boran...
Scheme 29: Palladium-catalyzed P–C cross-coupling reactions between primary or secondary phosphines and functi...
Scheme 30: Enantioselective synthesis of a P-chirogenic phosphine 108.
Scheme 31: Enantioselective arylation of silylphosphine 110 ((R,R)-Et-FerroTANE = 1,1'-bis((2R,4R)-2,4-diethyl...
Scheme 32: Nickel-catalyzed arylation of diphenylphosphine 25d.
Scheme 33: Nickel-catalyzed synthesis of (R)-BINAP 116 (dppe = 1,2-bis(diphenylphosphino)ethane, DABCO = 1,4-d...
Scheme 34: Nickel-catalyzed cross-coupling between aryl bromides 119 and diphenylphosphine (25d) (dppp = 1,3-b...
Scheme 35: Stereocontrolled Pd(0)−Cu(I) cocatalyzed aromatic phosphorylation.
Scheme 36: Preparation of alkenylphosphines by hydrophosphination of alkynes.
Scheme 37: Palladium and nickel-catalyzed addition of P–H to alkynes 125a.
Scheme 38: Palladium-catalyzed asymmetric hydrophosphination of an alkyne 128.
Scheme 39: Ruthenium catalyzed hydrophosphination of propargyl alcohols 132 (cod = 1,5-cyclooctadiene).
Scheme 40: Cobalt-catalyzed hydrophosphination of alkynes 134a (acac = acetylacetone).
Scheme 41: Tandem phosphorus–carbon bond formation–oxyfunctionalization of substituted phenylacetylenes 125c (...
Scheme 42: Organolanthanide-catalyzed intramolecular hydrophosphination/cyclization of phosphinoalkynes 143.
Scheme 43: Hydrophosphination of alkynes 134c catalyzed by ytterbium-imine complexes 145 (hmpa = hexamethylpho...
Scheme 44: Calcium-mediated hydrophosphanylation of alkyne 134d.
Scheme 45: Formation and substitution of bromophosphine borane 151.
Scheme 46: General scheme for a nickel or copper catalyzed cross-coupling reaction.
Scheme 47: Copper-catalyzed synthesis of alkynylphosphines 156.
Beilstein J. Org. Chem. 2013, 9, 2265–2319, doi:10.3762/bjoc.9.265
Graphical Abstract
Scheme 1: Scaled industrial processes for the synthesis of simple pyridines.
Scheme 2: Synthesis of nicotinic acid from 2-methyl-5-ethylpyridine (1.11).
Scheme 3: Synthesis of 3-picoline and nicotinic acid.
Scheme 4: Synthesis of 3-picoline from 2-methylglutarodinitrile 1.19.
Scheme 5: Picoline-based synthesis of clarinex (no yields reported).
Scheme 6: Mode of action of proton-pump inhibitors and structures of the API’s.
Scheme 7: Hantzsch-like route towards the pyridine rings in common proton pump inhibitors.
Figure 1: Structures of rosiglitazone (1.40) and pioglitazone (1.41).
Scheme 8: Synthesis of rosiglitazone.
Scheme 9: Syntheses of 2-pyridones.
Scheme 10: Synthesis and mechanism of 2-pyrone from malic acid.
Scheme 11: Polymer-assisted synthesis of rosiglitazone.
Scheme 12: Synthesis of pioglitazone.
Scheme 13: Meerwein arylation reaction towards pioglitazone.
Scheme 14: Route towards pioglitazone utilising tyrosine.
Scheme 15: Route towards pioglitazone via Darzens ester formation.
Scheme 16: Syntheses of the thiazolidinedione moiety.
Scheme 17: Synthesis of etoricoxib utilising Negishi and Stille cross-coupling reactions.
Scheme 18: Synthesis of etoricoxib via vinamidinium condensation.
Figure 2: Structures of nalidixic acid, levofloxacin and moxifloxacin.
Scheme 19: Synthesis of moxifloxacin.
Scheme 20: Synthesis of (S,S)-2,8-diazabicyclo[4.3.0]nonane 1.105.
Scheme 21: Synthesis of levofloxacin.
Scheme 22: Alternative approach to the levofloxacin core 1.125.
Figure 3: Structures of nifedipine, amlodipine and clevidipine.
Scheme 23: Mg3N2-mediated synthesis of nifedipine.
Scheme 24: Synthesis of rac-amlodipine as besylate salt.
Scheme 25: Aza Diels–Alder approach towards amlodipine.
Scheme 26: Routes towards clevidipine.
Figure 4: Examples of piperidine containing drugs.
Figure 5: Discovery of tiagabine based on early leads.
Scheme 27: Synthetic sequences to tiagabine.
Figure 6: Structures of solifenacin (2.57) and muscarine (2.58).
Scheme 28: Enantioselective synthesis of solifenacin.
Figure 7: Structures of DPP-4 inhibitors of the gliptin-type.
Scheme 29: Formation of inactive diketopiperazines from cis-rotameric precursors.
Figure 8: Co-crystal structure of carmegliptin bound in the human DPP-4 active site (PDB 3kwf).
Scheme 30: Improved route to carmegliptin.
Figure 9: Structures of lamivudine and zidovudine.
Scheme 31: Typical routes accessing uracil, thymine and cytosine.
Scheme 32: Coupling between pyrimidones and riboses via the Vorbrüggen nucleosidation.
Scheme 33: Synthesis of lamivudine.
Scheme 34: Synthesis of raltegravir.
Scheme 35: Mechanistic studies on the formation of 3.22.
Figure 10: Structures of selected pyrimidine containing drugs.
Scheme 36: General preparation of pyrimidines and dihydropyrimidones.
Scheme 37: Synthesis of imatinib.
Scheme 38: Flow synthesis of imatinib.
Scheme 39: Syntheses of erlotinib.
Scheme 40: Synthesis of erlotinib proceeding via Dimroth rearrangement.
Scheme 41: Synthesis of lapatinib.
Scheme 42: Synthesis of rosuvastatin.
Scheme 43: Alternative preparation of the key aldehyde towards rosuvastatin.
Figure 11: Structure comparison between nicotinic acetylcholine receptor agonists.
Scheme 44: Syntheses of varenicline and its key building block 4.5.
Scheme 45: Synthetic access to eszopiclone and brimonidine via quinoxaline intermediates.
Figure 12: Bortezomib bound in an active site of the yeast 20S proteasome ([114], pdb 2F16).
Scheme 46: Asymmetric synthesis of bortezomib.
Figure 13: Structures of some prominent piperazine containing drugs.
Figure 14: Structural comparison between the core of aplaviroc (4.35) and a type-1 β-turn (4.36).
Scheme 47: Examplary synthesis of an aplaviroc analogue via the Ugi-MCR.
Scheme 48: Syntheses of azelastine (5.1).
Figure 15: Structures of captopril, enalapril and cilazapril.
Scheme 49: Synthesis of cilazapril.
Figure 16: Structures of lamotrigine, ceftriaxone and azapropazone.
Scheme 50: Synthesis of lamotrigine.
Scheme 51: Alternative synthesis of lamotrigine (no yields reported).
Figure 17: Structural comparison between imiquimod and the related adenosine nucleoside.
Scheme 52: Conventional synthesis of imiquimod (no yields reported).
Scheme 53: Synthesis of imiquimod.
Scheme 54: Synthesis of imiquimod via tetrazole formation (not all yields reported).
Figure 18: Structures of various anti HIV-medications.
Scheme 55: Synthesis of abacavir.
Figure 19: Structures of diazepam compared to modern replacements.
Scheme 56: Synthesis of ocinaplon.
Scheme 57: Access to zaleplon and indiplon.
Scheme 58: Different routes towards the required N-methylpyrazole 6.65 of sildenafil.
Scheme 59: Polymer-supported reagents in the synthesis of key aminopyrazole 6.72.
Scheme 60: Early synthetic route to sildenafil.
Scheme 61: Convergent preparations of sildenafil.
Figure 20: Comparison of the structures of sildenafil, tadalafil and vardenafil.
Scheme 62: Short route to imidazotriazinones.
Scheme 63: Alternative route towards vardenafils core imidazotriazinone (6.95).
Scheme 64: Bayer’s approach to the vardenafil core.
Scheme 65: Large scale synthesis of vardenafil.
Scheme 66: Mode of action of temozolomide (6.105) as methylating agent.
Scheme 67: Different routes to temozolomide.
Scheme 68: Safer route towards temozolomide.
Figure 21: Some unreported heterocyclic scaffolds in top market drugs.
Beilstein J. Org. Chem. 2013, 9, 1977–2001, doi:10.3762/bjoc.9.234
Graphical Abstract
Scheme 1: Amine radical cations’ mode of reactivity.
Scheme 2: Reductive quenching of photoexcited Ru complexes by Et3N.
Scheme 3: Photoredox aza-Henry reaction.
Scheme 4: Formation of iminium ions using BrCCl3 as stoichiometric oxidant.
Scheme 5: Oxidative functionalization of N-aryltetrahydroisoquinolines using Eosin Y.
Scheme 6: Synthetic and mechanistic studies of Eosin Y-catalyzed aza-Henry reaction.
Scheme 7: Oxidative functionalization of N-aryltetrahydroisoquinolines using RB and GO.
Scheme 8: Merging Ru-based photoredox catalysis and Lewis base catalysis for the Mannich reaction.
Scheme 9: Merging Au-based photoredox catalysis and Lewis base catalysis for the Mannich reaction.
Scheme 10: Merging Ru-based photoredox catalysis and Cu-catalyzed alkynylation reaction.
Scheme 11: Merging Ru-based photoredox catalysis and NHC catalysis.
Scheme 12: 1,3-Dipolar cycloaddition of photogenically formed azomethine ylides.
Scheme 13: Plausible mechanism for photoredox 1,3-dipolar cycloaddition.
Scheme 14: Photoredox-catalyzed cascade reaction for the synthesis of fused isoxazolidines.
Scheme 15: Plausible mechanism for the photoredox-catalyzed cascade reaction.
Scheme 16: Photoredox-catalyzed α-arylation of glycine derivatives.
Scheme 17: Photoredox-catalyzed α-arylation of amides.
Scheme 18: Intramolecular interception of iminium ions by sulfonamides.
Scheme 19: Intramolecular interception of iminium ions by alcohols and sulfonamides.
Scheme 20: Intermolecular interception of iminium ions by phosphites.
Scheme 21: Photoredox-catalyzed oxidative phosphonylation by Eosin Y.
Scheme 22: Conjugated addition of α-amino radicals to Michael acceptors.
Scheme 23: Conjugated addition of α-amino radicals to Michael acceptors assisted by a Brønsted acid.
Scheme 24: Conjugated addition of α-amino radicals derived from anilines to Michael acceptors.
Scheme 25: Oxygen switch between two pathways involving α-amino radicals.
Scheme 26: Interception of α-amino radicals by azodicarboxylates.
Scheme 27: α-Arylation of amines.
Scheme 28: Plausible mechanism for α-arylation of amines.
Scheme 29: Photoinduced C–C bond cleavage of tertiary amines.
Scheme 30: Photoredox cleavage of C–C bonds of 1,2-diamines.
Scheme 31: Proposed mechanism photoredox cleavage of C–C bonds.
Scheme 32: Intermolecular [3 + 2] annulation of cyclopropylamines with olefins.
Scheme 33: Proposed mechanism for intermolecular [3 + 2] annulation.
Scheme 34: Photoinduced clevage of N–N bonds of aromatic hydrazines and hydrazides.
Beilstein J. Org. Chem. 2013, 9, 155–165, doi:10.3762/bjoc.9.18
Graphical Abstract
Scheme 1: Activation of amine-bonded Michael acceptors by protonation versus Lewis acid interaction.
Scheme 2: Synthesis of 4-hydroxycoumarin derivatives by Michael addition [19-27].
Scheme 3: Precatalysts 5–8 and synthesis from chiral 1,2-diamines and 2-sulfobenzoic anhydrides.
Figure 1: X-ray crystallographic structure of 5. The conformation of the 2-sulfobenzoic moiety is fixed by hy...
Figure 2: Michael acceptors employed as substrates in the nucleophilic addition of 4-hydroxycoumarin (1).
Scheme 4: Computationally analyzed pathways A (C-protonation), and B (N-protonation), arising from the additi...
Scheme 5: Computed energy profile for reaction path A (C-protonation) and B (N-protonation) corresponding to ...
Figure 3: Enantio-determining transition states arising from the addition of 4-hydroxycoumarin to cyclohexeno...
Figure 4: The competing enantio-determining transition structures TS-14a and TS-14g. The reason for the desta...
Beilstein J. Org. Chem. 2012, 8, 1668–1694, doi:10.3762/bjoc.8.191
Graphical Abstract
Figure 1: Some representative molecules having chromene, thiochromene or 1,2-dihydroquinolin structural motif...
Figure 2: Screened chiral proline and its derivatives as organocatalysts. Rb = rubidium.
Figure 3: Screened chiral bifunctional thiourea, its derivatives, cinchona alkaloids and other organocatalyst...
Scheme 1: Diarylprolinolether-catalyzed tandem oxa-Michael–aldol reaction reported by Arvidsson.
Scheme 2: Tandem oxa-Michael–aldol reaction developed by Córdova.
Scheme 3: Domino oxa-Michael-aldol reaction developed by Wei and Wang.
Scheme 4: Chiral amine/chiral acid catalyzed tandem oxa-Michael–aldol reaction developed by Xu et al.
Scheme 5: Modified diarylproline ether as amino catalyst in oxa-Michael–aldol reaction as reported by Xu and ...
Scheme 6: Chiral secondary amine promoted oxa-Michael–aldol cascade reactions as reported by Wang and co-work...
Scheme 7: Reaction of salicyl-N-tosylimine with aldehydes by domino oxa-Michael/aza-Baylis–Hillman reaction, ...
Scheme 8: Silyl prolinol ether-catalyzed oxa-Michael–aldol tandem reaction of alkynals with salicylaldehydes ...
Scheme 9: Oxa-Michael–aldol sequence for the synthesis of tetrahydroxanthones developed by Córdova.
Scheme 10: Synthesis of tetrahydroxanthones developed by Xu.
Scheme 11: Diphenylpyrrolinol trimethylsilyl ether catalyzed oxa-Michael–Michael–Michael–aldol reaction for th...
Scheme 12: Enantioselective cascade oxa-Michael–Michael reaction of alkynals with 2-(E)-(2-nitrovinyl)-phenols...
Scheme 13: Domino oxa-Michael–Michael–Michael–aldol reaction of 2-(2-nitrovinyl)-benzene-1,4-diol with α,β-uns...
Scheme 14: Tandem oxa-Michael–Henry reaction catalyzed by organocatalyst and salicylic acid, as reported by Xu....
Scheme 15: Asymmetric synthesis of nitrochromenes from salicylaldehydes and β-nitrostyrene, as reported by San...
Scheme 16: Domino Michael–aldol reaction between salicyaldehydes with β-nitrostyrene, as reported by Das and c...
Scheme 17: Enantioselective synthesis of 2-aryl-3-nitro-2H-chromenes, as reported by Schreiner.
Scheme 18: (S)-diphenylpyrrolinol silyl ether-promoted cascade thio-Michael–aldol reactions, as reported by Wa...
Scheme 19: Organocatalytic asymmetric domino Michael–aldol condensation of mercaptobenzaldehyde and α,β-unsatu...
Scheme 20: Organocatalytic asymmetric domino Michael–aldol condensation between mercaptobenzaldehyde and α,β-u...
Scheme 21: Hydrogen-bond-mediated Michael–aldol reaction of 2-mercaptobenzaldehyde with α,β-unsaturated oxazol...
Scheme 22: Domino Michael–aldol reaction of 2-mercaptobenzaldehydes with maleimides catalyzed by cinchona alka...
Scheme 23: Domino thio-Michael–aldol reaction between 2-mercaptoacetophenone and enals developed by Córdova an...
Scheme 24: Enantioselective tandem Michael–Henry reaction of 2-mercaptobenzaldehyde with β-nitrostyrenes repor...
Scheme 25: Enantioselective tandem Michael–Knoevenagel reaction between 2-mercaptobenzaldehydes and benzyliden...
Scheme 26: Cinchona alkaloid thiourea catalyzed Michael–Michael cascade reaction, as reported by Wang and co-w...
Scheme 27: Domino aza-Michael–aldol reaction between 2-aminobenzaldehydes and α,β-unsaturated aldehydes, as re...
Scheme 28: (S)-Diphenylprolinol TES ether-promoted aza-Michael–aldol cascade reaction, as developed by Wang’s ...
Scheme 29: Domino aza-Michael–aldol reaction reported by Hamada.
Scheme 30: Organocatalytic asymmetric synthesis of 3-nitro-1,2-dihydroquinolines by a dual activation protocol...
Scheme 31: Asymmetric synthesis of 3-nitro-1,2-dihydroquinolines by cascade aza-Michael–Henry–dehydration reac...
Beilstein J. Org. Chem. 2012, 8, 1452–1457, doi:10.3762/bjoc.8.165
Graphical Abstract
Figure 1: The conjugated addition to unsaturated 1,4-diketone 1.
Figure 2: Organocatalysts screened.
Figure 3: Proposed transition state.
Figure 4: Calculated (red) and experimental (blue) IR (A) and VCD spectrum (B) of compound (R)-3a.
Beilstein J. Org. Chem. 2012, 8, 1406–1442, doi:10.3762/bjoc.8.163
Graphical Abstract
Scheme 1: Reactions for the methyl cation affinity (MCA) of a neutral Lewis base (1a), an anionic Lewis base ...
Figure 1: MCA values of monosubstituted amines of general formula Me2N(CH2)nH (n = 1–7, in kJ/mol).
Scheme 2: Systematic dependence of MCA.
Scheme 3: Trends in amine MCA values.
Figure 2: Eclipsing interactions in the best conformation of N+Me(iPr)3 (16Me) (left), and the corresponding ...
Scheme 4: General expression for the chain-length dependence of MCA values.
Figure 3: MCA values of monosubstituted phosphanes of general formula Me2P(CH2)nH (n = 1–8, in kJ/mol).
Figure 4: MCA values of monosubstituted phosphanes of general formula PMe2(CH(CH2)n+1) (n = 1–8, in kJ/mol).
Figure 5: The MCA values of n-butyldiphenylphosphane (102) and its (αα-/ββ-/γγ-) dimethylated analogues.
Figure 6: MCA values of phosphanes Me2P–NR2 with cyclic and acyclic amine substituents.
Figure 7: MCA values of phosphanes PMe2R connected to α,α- and β,β-position of nitrogen containing cyclic sub...
Scheme 5: Reactions for the benzhydryl cation affinity (BHCA) of a Lewis base (5a) and pyridine (5b).
Figure 8: Comparison of BHCA values (kJ/mol) and nucleophilicity parameters N for sterically unbiased pyridin...
Scheme 6: Reactions for the trityl cation affinity (THCA) of a Lewis base (6a) and pyridine (6b).
Figure 9: Comparison of MCA, BHCA, and TCA values of selected Lewis bases.
Scheme 7: Correlations of BHCA/TCA values with the respective MCA data for sterically unbiased systems (exclu...
Figure 10: Scheme for the angle d(RXRR) measurements.
Scheme 8: Reactions for the Mosher's cation affinity (MOSCA) of a Lewis base.
Scheme 9: Reactions for the acetyl cation affinity (ACA) of a Lewis base (9a) and pyridine (9b).
Figure 11: Structure of the acetylated pyridine 380 (380Ac).
Scheme 10: Reaction for the Michael-acceptor affinity (MAA) of a Lewis base.
Figure 12: Inverted reaction free energies for the addition of N- and P-based Lewis bases to three different M...
Figure 13: Correlation between MCA values and affinity values towards three different Michael acceptors.
Scheme 11: (a) General definition for a methyl cation transfer reaction between Lewis bases LB1 and LB2, and (...
Figure 14: The energetically best conformations of Pn-Bu3 (120_1, top) and (120_2, bottom).
Figure 15: Relative order of the conformations 120_1 to 120_7 depending on the level of theory.
Figure 16: The structure of the energetically best conformations of 120Me.
Beilstein J. Org. Chem. 2012, 8, 1360–1365, doi:10.3762/bjoc.8.157
Graphical Abstract
Figure 1: Cinchona alkaloid-derived catalysts screened for condition optimization (Table 1).
Scheme 1: A one-pot synthesis of enantioenriched 3,3-diaryloxindoles.
Beilstein J. Org. Chem. 2012, 8, 850–860, doi:10.3762/bjoc.8.95
Graphical Abstract
Figure 1: Overview of the DOS strategy.
Scheme 1: Synthesis of linear cyclisation precursors 1–4.
Scheme 2: AlCl3 catalysed tandem Boc-removal/bicyclisation processes; the yields quoted refer to the isolated...
Scheme 3: (a) AlCl3 catalysed formation of tricyclic alkaloid 10 along with an X-ray crystal structure of 10;...
Scheme 4: (a) Optimal conditions to obtain trans-8 and 10 and the control experiments carried out to probe th...
Scheme 5: DOS of 5-5-6 and 5-6-6 tricyclic alkaloids 13 and 14.
Scheme 6: Total synthesis of myrrhine, epi-myrrhine and myrrhine-N-oxide.
Scheme 7: Use of nitromethane in DOS: Synthesis of meso-diphenylpyrrolidizine 17.
Scheme 8: Use of Tris as a substrate for DOS: Synthesis of decorated morpholines 22 and 23.
Beilstein J. Org. Chem. 2011, 7, 1387–1406, doi:10.3762/bjoc.7.163
Graphical Abstract
Scheme 1: Synthesis of substituted amides.
Scheme 2: Synthesis of ketocarbamates and imidazolones.
Scheme 3: Access to β-lactams.
Scheme 4: Access to β-lactams with increased structural diversity.
Scheme 5: Synthesis of imidazolinium salts.
Scheme 6: Access to the indenamine core.
Scheme 7: Synthesis of substituted tetrahydropyridines.
Scheme 8: Synthesis of more substituted tetrahydropyridines.
Scheme 9: Synthesis of chiral tetrahydropyridines.
Scheme 10: Preparation of α-aminonitrile by a catalyzed Strecker reaction.
Scheme 11: Synthesis of spiroacetals.
Scheme 12: Synthesis of masked 3-aminoindan-1-ones.
Scheme 13: Synthesis of homoallylic amines and α-aminoesters.
Scheme 14: Preparation of 1,2-dihydroisoquinolin-1-ylphosphonates.
Scheme 15: Pyrazole elaboration by cycloaddition of hydrazines with alkynones generated in situ.
Scheme 16: An alternative approach to pyrazoles involving hydrazine cycloaddition.
Scheme 17: Synthesis of pyrroles by cyclization of propargyl amines.
Scheme 18: Isoindolone and phthalazone synthesis by cyclization of acylhydrazides.
Scheme 19: Sultam synthesis by cyclization of sulfonamides.
Scheme 20: Synthesis of sulfonamides by aminosulfonylation of aryl iodides.
Scheme 21: Pyrrolidine synthesis by carbopalladation of allylamines.
Scheme 22: Synthesis of indoles through a sequential C–C coupling/desilylation–coupling/cyclization reaction.
Scheme 23: Synthesis of indoles by a site selective Pd/C catalyzed cross-coupling approach.
Scheme 24: Synthesis of isoindolin-1-one derivatives through a sequential Sonogashira coupling/carbonylation/h...
Scheme 25: Synthesis of pyrroles through an allylic amination/Sonogashira coupling/hydroamination reaction.
Scheme 26: Synthesis of indoles through a Sonogashira coupling/cyclofunctionalization reaction.
Scheme 27: Synthesis of indoles through a one-pot two-step Sonogashira coupling/cyclofunctionalization reactio...
Scheme 28: Synthesis of α-alkynylindoles through a Pd-catalyzed Sonogashira/double C–N coupling reaction.
Scheme 29: Synthesis of indoles through a Pd-catalyzed sequential alkenyl amination/C-arylation/N-arylation.
Scheme 30: Synthesis of N-aryl-2-benzylpyrrolidines through a sequential N-arylation/carboamination reaction.
Scheme 31: Synthesis of phenothiazine derivatives through a one-pot palladium-catalyzed double C–N arylation i...
Scheme 32: Synthesis of substituted imidazolidinones through a palladium-catalyzed three-component reaction of...
Scheme 33: Synthesis of 2,3-diarylated amines through a palladium-catalyzed four-component reaction involving ...
Scheme 34: Synthesis of rolipram involving a Pd-catalyzed three-component reaction.
Scheme 35: Synthesis of seven-membered ring lactams through a Pd-catalyzed amination/intramolecular cyclocarbo...
Beilstein J. Org. Chem. 2011, 7, 442–495, doi:10.3762/bjoc.7.57
Graphical Abstract
Figure 1: Structures of atorvastatin and other commercial statins.
Figure 2: Structure of compactin.
Scheme 1: Synthesis of pentasubstituted pyrroles.
Scheme 2: [3 + 2] Cycloaddition to prepare 5-isopropylpyrroles.
Scheme 3: Regiospecific [3 + 2] cycloaddition to prepare the pyrrole scaffold.
Scheme 4: Formation of the pyrrole core of atorvastatin via [3 + 2] cycloaddition.
Scheme 5: Formation of pyrrole 33 via the Paal–Knorr reaction.
Scheme 6: Convergent synthesis towards atorvastatin.
Figure 3: Binding pocket of sunitinib in the TRK KIT.
Scheme 7: Synthesis of sunitinib.
Scheme 8: Alternative synthesis of sunitinib.
Scheme 9: Key steps in the syntheses of sumatriptan and zolmitriptan.
Scheme 10: Introduction of the N,N-dimethylaminoethyl side chain.
Scheme 11: Japp–Klingemann reaction in the synthesis of sumatriptan.
Scheme 12: Synthesis of the intermediate sulfonyl chlorides 62 and 63.
Scheme 13: Alternative introduction of the sulfonamide.
Scheme 14: Negishi-type coupling to benzylic sulfonamides.
Scheme 15: Heck reaction used to introduce the sulfonamide side chain of naratriptan.
Scheme 16: Synthesis of the oxazolinone appendage of zolmitriptan.
Scheme 17: Grandberg indole synthesis used in the preparation of rizatriptan.
Scheme 18: Improved synthesis of rizatriptan.
Scheme 19: Larock-type synthesis of rizatriptan.
Scheme 20: Synthesis of eletriptan.
Scheme 21: Heck coupling for the indole system in eletriptan.
Scheme 22: Attempted Fischer indole synthesis of elatriptan.
Scheme 23: Successful Fischer indole synthesis for eletriptan.
Scheme 24: Mechanistic rationale for the Bischler–Möhlau reaction.
Scheme 25: Bischler-type indole synthesis used in the fluvastatin sodium synthesis.
Scheme 26: Palladium-mediated synthesis of ondansetron.
Scheme 27: Fischer indole synthesis of ondansetron.
Scheme 28: Optimised Pictet–Spengler reaction towards tadalafil.
Figure 4: Structures of carvedilol 136 and propranolol 137.
Scheme 29: Synthesis of the carbazole core of carvedilol.
Scheme 30: Alternative syntheses of 4-hydroxy-9H-carbazole.
Scheme 31: Convergent synthesis of etodolac.
Scheme 32: Alternative synthesis of etodolac.
Figure 5: Structures of imidazole-containing drugs.
Scheme 33: Synthesis of functionalised imidazoles towards losartan.
Scheme 34: Direct synthesis of the chlorinated imidazole in losartan.
Scheme 35: Synthesis of trisubstituted imidazoles.
Scheme 36: Preparation of the imidazole ring in olmesartan.
Scheme 37: Synthesis of ondansetron.
Scheme 38: Alternative route to ondansetron and its analogues.
Scheme 39: Proton pump inhibitors and synthesis of esomeprazole.
Scheme 40: Synthesis of benzimidazole core pantoprazole.
Figure 6: Structure of rabeprazole 194.
Scheme 41: Synthesis of candesartan.
Scheme 42: Alternative access to the candesartan key intermediate 216.
Scheme 43: .Medicinal chemistry route to telmisartan.
Scheme 44: Improved synthesis of telmisartan.
Scheme 45: Synthesis of zolpidem.
Scheme 46: Copper-catalysed 3-component coupling towards zolpidem.
Figure 7: Structure of celecoxib.
Scheme 47: Preparation of celecoxib.
Scheme 48: Alternative synthesis of celecoxib.
Scheme 49: Regioselective access to celecoxib.
Scheme 50: Synthesis of pazopanib.
Scheme 51: Syntheses of anastrozole, rizatriptan and letrozole.
Scheme 52: Regioselective synthesis of anastrozole.
Scheme 53: Triazine-mediated triazole formation towards anastrozole.
Scheme 54: Alternative routes to 1,2,4-triazoles.
Scheme 55: Initial synthetic route to sitagliptin.
Figure 8: Binding of sitagliptin within DPP-IV.
Scheme 56: The process route to sitagliptin key intermediate 280.
Scheme 57: Synthesis of maraviroc.
Scheme 58: Synthesis of alprazolam.
Scheme 59: The use of N-nitrosoamidine derivatives in the preparation of fused benzodiazepines.
Figure 9: Structures of itraconazole, ravuconazole and voriconazole.
Scheme 60: Synthesis of itraconazole.
Scheme 61: Synthesis of rufinamide.
Scheme 62: Representative tetrazole formation in valsartan.
Figure 10: Structure of tetrazole containing olmesartan, candesartan and irbesartan.
Scheme 63: Early stage introduction of the tetrazole in losartan.
Scheme 64: Synthesis of cilostazol.
Figure 11: Structure of cefdinir.
Scheme 65: Semi-synthesis of cefdinir.
Scheme 66: Thiazole syntheses towards ritonavir.
Scheme 67: Synthesis towards pramipexole.
Scheme 68: Alternative route to pramipexole.
Scheme 69: Synthesis of famotidine.
Scheme 70: Efficient synthesis of the hyperuricemic febuxostat.
Scheme 71: Synthesis of ziprasidone.
Figure 12: Structure of mometasone.
Scheme 72: Industrial access to 2-furoic acid present in mometasone.
Scheme 73: Synthesis of ranitidine from furfuryl alcohol.
Scheme 74: Synthesis of nitrofurantoin.
Scheme 75: Synthesis of benzofuran.
Scheme 76: Synthesis of amiodarone.
Scheme 77: Synthesis of raloxifene.
Scheme 78: Alternative access to the benzo[b]thiophene core of raloxifene.
Scheme 79: Gewald reaction in the synthesis of olanzapine.
Scheme 80: Alternative synthesis of olanzapine.
Figure 13: Access to simple thiophene-containing drugs.
Scheme 81: Synthesis of clopidogrel.
Scheme 82: Pictet–Spengler reaction in the preparation of tetrahydrothieno[3,2-c]pyridine (422).
Scheme 83: Alternative synthesis of key intermediate 422.
Figure 14: Co-crystal structures of timolol (left) and carazolol (right) in the β-adrenergic receptor.
Scheme 84: Synthesis of timolol.
Scheme 85: Synthesis of tizanidine 440.
Scheme 86: Synthesis of leflunomide.
Scheme 87: Synthesis of sulfamethoxazole.
Scheme 88: Synthesis of risperidone.
Figure 15: Relative abundance of selected transformations.
Figure 16: The abundance of heterocycles within top 200 drugs (5-membered rings).
Beilstein J. Org. Chem. 2011, 7, 173–178, doi:10.3762/bjoc.7.24
Graphical Abstract
Figure 1: Examples of azole derivatives as important therapeutic agents.
Scheme 1: Michael-type addition of azoles of broad-scale acidity 1a–h to methyl acrylate (2) under basic cond...
Scheme 2: Chemical evidence for a regioselective Michael-type addition of 4(5)-nitroimidazole (1c) to methyl ...
Beilstein J. Org. Chem. 2010, 6, No. 37, doi:10.3762/bjoc.6.37
Graphical Abstract
Figure 1: Boronolide (1), boronolide analogues 2–3 and gem-difluoromethylenated analogues 4–7.
Scheme 1: Retrosynthetic analysis of target molecules 4–7.
Scheme 2: Synthesis of target molecules 4–5.
Scheme 3: Synthesis of target molecules 6–7.