The enantioselectiveStreckerreaction of N-diphenylphosphinoyl ketoimines has been achieved by use of in situ prepared chiral N,N‘-dioxide catalyst from l-piperidinamide 3f and m-chloroperoxybenzoic acid (m-CPBA). Excellent yields (up to 99%) and high enantioselectivities (up to 92% ee) were obtained. In particular, in situ prepared catalyst with readily available chiral material made the procedure
Asymmetric catalysis: A facileenantioselective Strecker reaction of ketimines with trimethylsilyl cyanide (TMSCN) was realized by employing chiral (S)‐BNPNa 3 e and PBAP as an additive (see image). A wide substrate scope and good‐to‐excellent enantioselectivities were achieved.
The enantioselectivephospha-Mannichreaction of diethyl phosphite to unactivated N-DPP-protected ketimines catalyzed by a bifunctional iminophosphorane (BIMP) superbase organocatalyst is described. The reaction is applicable to ketimines bearing electron-rich and electron-poor aryl substituents and occurs with excellent yields and moderate enantioselectivities under mild reaction conditions.
Enantioselective Hydrosilylation of Imines Catalyzed by Chiral Zinc Acetate Complexes
作者:Agata Bezłada、Marcin Szewczyk、Jacek Mlynarski
DOI:10.1021/acs.joc.5b02613
日期:2016.1.4
A series of zinc acetate complexes with optically pure diphenylethanediamine (DPEDA)-derived ligands have been employed as enantioselectivecatalyst for the hydrosilylation of various imines. High control of stereoselectivity (up to 97% ee) and excellent yields (up to 96%) were gained for a broad range of N-phosphinoylimines by using (R,R)-N,N′-dibenzyl-1,2-diphenylethane-1,2-diamine. This is the first
Catalytic Enantioselective Mannich-type Reactions of Ketoimines
作者:Yutaka Suto、Motomu Kanai、Masakatsu Shibasaki
DOI:10.1021/ja068226a
日期:2007.1.1
(10 mol %) and (EtO)2Si(OAc)2 as the trapping reagent (1 equiv) of the intermediate copper amide (generated via the addition of a copper enolate to the imine). The trapping reagent significantly facilitated the catalyst turnover. Excellent enantioselectivity was produced from a range of aromatic ketoimines, including heteroaromatic and ethyl-substituted ketoimines. The optimized conditions for aliphatic