Search results
Search for "dynamic kinetic asymmetric transformation" in Full Text gives 6 result(s) in Beilstein Journal of Organic Chemistry.
Synthesis of pyrrolidine-based hamamelitannin analogues as quorum sensing inhibitors in Staphylococcus aureus
- Jakob Bouton,
- Kristof Van Hecke,
- Reuven Rasooly and
- Serge Van Calenbergh
Beilstein J. Org. Chem. 2018, 14, 2822–2828, doi:10.3762/bjoc.14.260
- previous attempts to synthesize 9 failed due to side reactions caused by the strongly electron-withdrawing properties of the nosyl group. The successful synthesis starts with a Pd-catalyzed dynamic kinetic asymmetric transformation of racemic butadiene monoepoxide to 12, employing phthalimide as
Graphical Abstract
Figure 1: Structures of hamamelitannin (1), lead compound 2 and target compounds 3.
Scheme 1: Proposed strategy for the synthesis of the target analogues.
Scheme 2: Synthesis of fragment 9. Reagents and conditions: a) phthalimide, Pd2(allyl)2Cl2, ligand 15, Na2CO3...
Scheme 3: Synthesis of fragment 10. Reagents and conditions: a) TBSCl, NaH, THF, rt; b) phthalimide, PPh3, DE...
Scheme 4: Coupling of 9 and 10 and attempted ring-closing metathesis. Reagents and conditions: a) PPh3, DEAD,...
Scheme 5: Synthesis of alternative eastern fragment 23. Reagents and conditions: a) TBSCl, imidazole, CH2Cl2,...
Scheme 6: Synthesis of 4. Reagents and conditions: a) PPh3, DEAD, THF, 0 °C to rt; b) Grubbs–Hoveyda II (5 mo...
Scheme 7: Late stage functionalization of the pyrrolidine nitrogen. Reagents and conditions: A) (masked) alde...
Figure 2: Molecular X-ray structure of 3a, showing thermal displacement ellipsoids at the 50% probability lev...
Cupreines and cupreidines: an established class of bifunctional cinchona organocatalysts
- Laura A. Bryant,
- Rossana Fanelli and
- Alexander J. A. Cobb
Beilstein J. Org. Chem. 2016, 12, 429–443, doi:10.3762/bjoc.12.46
- organocatalyst with comparable results. More recently, Johnson and co-worker used the o-toluoyl derived organocatalyst CPD-33 to effect a dynamic kinetic asymmetric transformation of racemic β-bromo-α-keto esters 32 (Scheme 9a) [35]. The mechanism, deduced from deuterium labeling studies, proposes that one of
- . A cupreidine derived catalyst induces a dynamic kinetic asymmetric transformation. Cupreine derivative 38 has been used in an organocatalytic asymmetric Friedel–Crafts reaction. Examples of 6’-OH cinchona alkaloid catalyzed processes include: (a) Deng’s addition of dimethyl malonate into
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...
Copper-catalysed asymmetric allylic alkylation of alkylzirconocenes to racemic 3,6-dihydro-2H-pyrans
- Emeline Rideau and
- Stephen P. Fletcher
Beilstein J. Org. Chem. 2015, 11, 2435–2443, doi:10.3762/bjoc.11.264
- assistance of a design of experiments statistical approach (83% ee, 12% yield). 1H NMR spectroscopy was used to gain insight into the reaction mechanisms. Keywords: allylic alkylation; asymmetric catalysis; copper; design of experiments; dynamic kinetic asymmetric transformation; heterocycles; Schwartz
Graphical Abstract
Scheme 1: Previously reported Cu-AAA of alkylzirconium reagents to racemic allyl chlorides [26] and this work.
Figure 1: DoE from 3,6-dihydro-2H-pyran-3-yl diethyl phosphate (2d). Conditions: 4-phenyl-1-butene (2.5 equiv...
Scheme 2: Scope of nucleophiles. Conditions: alkene (2.5 equiv), Cp2ZrHCl (2.0 equiv), 3-chloro-3,6-dihydro-2H...
Figure 2: Reaction kinetics as monitored by in situ 1H NMR spectroscopy from 3-chloro-3,6-dihydro-2H-pyran (2a...
Figure 3: Reaction kinetics as monitored by in situ 1H NMR spectroscopy from 3,6-dihydro-2H-pyran-3-yl diethy...
Figure 4: Kinetic ee analysis using 2a. ee of reaction with 3-chloro-3,6-dihydro-2H-pyran (2a) as measured by...
Figure 5: Kinetic ee analysis using 2d. ee of reaction with 3,6-dihydro-2H-pyran-3-yl diethyl phosphate (2d) ...
Chiral phosphines in nucleophilic organocatalysis
- Yumei Xiao,
- Zhanhu Sun,
- Hongchao Guo and
- Ohyun Kwon
Beilstein J. Org. Chem. 2014, 10, 2089–2121, doi:10.3762/bjoc.10.218
- -substituted racemic allenoate also underwent the catalytic annulations smoothly through a dynamic kinetic asymmetric transformation, giving the desired products in high yields and moderate diastereoselectivities, albeit with somewhat decreased ee values. A transition-state model similar to Miller’s, mentioned
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.
Flow synthesis of phenylserine using threonine aldolase immobilized on Eupergit support
- Jagdish D. Tibhe,
- Hui Fu,
- Timothy Noël,
- Qi Wang,
- Jan Meuldijk and
- Volker Hessel
Beilstein J. Org. Chem. 2013, 9, 2168–2179, doi:10.3762/bjoc.9.254
- as low diastereoselectivity and product yield. To overcome this drawback of aldolases, dynamic kinetic asymmetric transformation has been carried out in which a bi-enzymatic process was performed to achieve a high yield of the product by shifting the reaction equilibrium [45]. Eupergit oxirane
Graphical Abstract
Scheme 1: Phenylserine synthesis.
Figure 1: Activity loss of TA immobilized by two different methods and as a free enzyme at 80 °C. Reproduced ...
Figure 2: Degree of immobilization versus incubation time.
Figure 3: Batch reaction using free enzyme. Reaction conditions: Reaction volume (10 mL), TA (2.7 mg, specifi...
Figure 4: Product inhibition study.
Figure 5: Effect of temperature on product yield. Reaction conditions: Reaction volume (0.250 mL), TA (1.1 mg...
Figure 6: Effect of flow rates on yield for immobilized enzymes in a packed bed microreactor (70 °C). Reactio...
Figure 7: Effect of residence time on yield for free enzymes in a Teflon tube microreactor at 70 °C. Reaction...
Figure 8: Long term enzyme stability at 70 °C. Reaction conditions: Reaction volume (0.250 mL), TA (1.1 mg, s...
Scheme 2: Synthesis of chiral α-aminoalcohol by telescoping aldolase reaction with decarboxylation.
Figure 9: Direct immobilization.
Figure 10: Indirect immobilization.
Figure 11: Flow reaction set-up using free enzyme.
Figure 12: Experimental setup for packed be microreactor.
Figure 13: Analysis of the four isomers of phenylserine on a chiral column.
Synthesis of axially chiral oxazoline–carbene ligands with an N-naphthyl framework and a study of their coordination with AuCl·SMe2
- Feijun Wang,
- Shengke Li,
- Mingliang Qu,
- Mei-Xin Zhao,
- Lian-Jun Liu and
- Min Shi
Beilstein J. Org. Chem. 2012, 8, 726–731, doi:10.3762/bjoc.8.81
- diaminocarbene) gold(I) complexes 3 derived from 3,3′-substituted 1,1′-binaphthalenyl-2,2′-diamine, and their application in the dynamic kinetic asymmetric transformation of propargyl esters, giving the corresponding substituted chromenes in up to 99% ee [12]. Our group also developed a new family of axially
Graphical Abstract
Figure 1: Chiral NHC–Au(I) complexes.
Figure 2: Axially chiral oxazoline–carbene ligands and their palladium complexes.
Scheme 1: Synthesis of axially chiral benzimidazole derivatives.
Figure 3: The coordination study of the NHC precursor (Sa,S)-7aa with metal salts by 1H NMR analysis of the c...
Figure 4: Solid-state molecular structure of (Sa,S)-16aa with thermal ellipsoids at the 30% probability level...
