Elsevier eBooks, Journal Year: 2019, Volume and Issue: unknown, P. 199 - 274
Published: Dec. 31, 2019
Language: Английский
Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 59(21), P. 8004 - 8014
Published: Dec. 2, 2019
Abstract Direct deprotonation represents an extremely simple, straightforward, and atom‐economic strategy to activate pronucleophiles bearing acidic proton. However, the difficulty often arises in activating with high p K a values by using conventional chiral tertiary amines. To overcome this challenge, handful of novel Brønsted superbases, including amidines, guanidines, cyclopropenimines, iminophosphoranes, have been discovered recent years. This minireview focuses on application these organo‐superbases catalytic asymmetric reactions weakly pronucleophiles, highlights their comparison amines, demonstrating highly efficient processes stereoselectivity controlled conversions superbases. The advantage new superbases brings great opportunity for developing more transformations pronucleophiles.
Language: Английский
Citations
59
Chemistry - A European Journal, Journal Year: 2021, Volume and Issue: 27(42), P. 10807 - 10825
Published: May 25, 2021
The renaissance of Brønsted superbases is primarily based on their pronounced capacity for a large variety chemical transformations under mild reaction conditions. Four major set screws are available the selective tuning basicity: nature basic center (N, P, …), degree electron donation by substituents to central atom, possibility charge delocalization, and energy gain hydrogen bonding. Within past decades, plethora neutral electron-rich phosphine phosphazene bases have appeared in literature. Their outstanding properties advantages over inorganic or charged now made them indispensable as auxiliary deprotonation processes. Herein, an update chemistry phosphines phosphazenes given. In addition, due widespread interest, use catalysis ligands coordination highlighted.
Language: Английский
Citations
44
The Chemical Record, Journal Year: 2020, Volume and Issue: 20(11), P. 1269 - 1296
Published: Sept. 15, 2020
Abstract Chiral thioethers is an important class of organosulfur molecules with extensive applications, especially in the field medicine and organic synthesis. This review discusses recent progress synthesis enantioenriched chiral hopes to be helpful for related research future. It summarized from compounds‐participating reaction types, including nucleophilic substitution, cross coupling, sulfa‐Michael addition, sulfenylation, asymmetric allylic reaction, Doyle‐Kirmse Pummerer‐type rearrangement, Smiles [2,3] Stevens Sommelet‐Hauser rearrangement.
Language: Английский
Citations
47
Chemistry - A European Journal, Journal Year: 2018, Volume and Issue: 24(72), P. 19156 - 19161
Published: Oct. 25, 2018
Switchable catalytic transformation of reactants can be a powerful approach towards diversity-orientated synthesis from easily available molecular synthons. Herein, an endogenous ligand-controlled, Pd-catalyzed allylic substitution allowing for either selective C-N or C-S bond formation using vinylethylene carbonates (VECs) and N-sulfonylhydrazones as coupling partners has been developed. This versatile methodology provides facile, divergent route the highly chemo- stereoselective functional sulfones sulfonohydrazides. The newly developed protocol features wide substrate scope (nearly 80 examples), broad group tolerance, potential late-stage functionalization bioactive compounds. isolation crystallographic analysis catalytically competent π-allyl Pd complex suggests that pathway leading to products proceeds through different manifold previously proposed VECs with nucleophiles.
Language: Английский
Citations
42
Chemistry - A European Journal, Journal Year: 2018, Volume and Issue: 24(50), P. 13110 - 13113
Published: July 4, 2018
Abstract An organocatalytic arylation of α‐ketoesters was developed on the basis umpolung strategy. Phosphazene P2‐ t Bu efficiently catalyzes three‐component coupling reaction α‐ketoesters, a silylated secondary phosphite, and electron‐deficient fluoroarenes to provide α‐hydroxyester derivatives possessing an aryl group at α‐position. The involves catalytic generation α‐oxygenated ester enolates from through [1,2]‐phospha‐Brook rearrangement followed by S N Ar reaction.
Language: Английский
Citations
31
Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 59(40), P. 17417 - 17422
Published: June 19, 2020
A bifunctional iminophosphorane (BIMP)-catalysed enantioselective synthesis of α,β-unsaturated cyclohexenones through a facially selective 1,3-prototropic shift β,γ-unsaturated prochiral isomers, under mild reaction conditions and in short times, on range structurally diverse substrates, is reported. α,β-Unsaturated cyclohexenone products primed for downstream derivatisation were obtained high yields (up to 99 %) consistently enantioselectivity % ee). Computational studies into the mechanism origins enantioselectivity, including multivariate linear regression TS energy, carried out data found be good agreement with experimental findings.
Language: Английский
Citations
27
Angewandte Chemie, Journal Year: 2019, Volume and Issue: 132(21), P. 8080 - 8090
Published: Dec. 2, 2019
Abstract Direct deprotonation represents an extremely simple, straightforward, and atom‐economic strategy to activate pronucleophiles bearing acidic proton. However, the difficulty often arises in activating with high p K a values by using conventional chiral tertiary amines. To overcome this challenge, handful of novel Brønsted superbases, including amidines, guanidines, cyclopropenimines, iminophosphoranes, have been discovered recent years. This minireview focuses on application these organo‐superbases catalytic asymmetric reactions weakly pronucleophiles, highlights their comparison amines, demonstrating highly efficient processes stereoselectivity controlled conversions superbases. The advantage new superbases brings great opportunity for developing more transformations pronucleophiles.
Language: Английский
Citations
20
Asian Journal of Organic Chemistry, Journal Year: 2019, Volume and Issue: 8(12), P. 2180 - 2183
Published: Nov. 2, 2019
Abstract An asymmetric [3+2] cycloaddition of racemic vinyl epoxides with N ‐benzothiazolimines has been presented under Pd‐catalysis. This transformation provides rapid access to highly functionalized oxazolidine scaffolds in generally good yields along high stereoselectivities (up 99% ee , 8.5 : 1 d.r.) mild conditions. The use chiral BINAP ligand enabled this a broad substrate tolerance.
Language: Английский
Citations
15
Angewandte Chemie, Journal Year: 2020, Volume and Issue: 132(40), P. 17570 - 17575
Published: June 19, 2020
Abstract A bifunctional iminophosphorane (BIMP)‐catalysed enantioselective synthesis of α,β‐unsaturated cyclohexenones through a facially selective 1,3‐prototropic shift β,γ‐unsaturated prochiral isomers, under mild reaction conditions and in short times, on range structurally diverse substrates, is reported. α,β‐Unsaturated cyclohexenone products primed for downstream derivatisation were obtained high yields (up to 99 %) consistently enantioselectivity % ee ). Computational studies into the mechanism origins enantioselectivity, including multivariate linear regression TS energy, carried out data found be good agreement with experimental findings.
Language: Английский
Citations
5
Elsevier eBooks, Journal Year: 2019, Volume and Issue: unknown, P. 199 - 274
Published: Dec. 31, 2019
Language: Английский
Citations
4