A diverse series of chiral bicyclic NHC/Ir complexes were prepared via a previously developed divergent synthesis of chiral imidazolium salts.
通过先前开发的立体选择性合成方法,一系列结构多样的手性双环NHC/Ir(金属铱)络合物得以制备。
Azetidine derivatives, their preparation and medicaments containing them
申请人:——
公开号:US20020035102A1
公开(公告)日:2002-03-21
The invention concerns compounds of formula (1) wherein: R represents a chain (A) or (B); R
1
is methyl or ethyl; R
2
is either an optionally substituted aromatic or an optionally substituted heteroaromatic ring; R
3
and R
4
, identical or different, are either an optionally substituted aromatic or an optionally substituted heteroaromatic ring; R′ represents a hydrogen atom or a —CO—alk radical, their optical isomers, their salts, their preparation and medicines containing them.
1
Chiral N-Heterocyclic Carbene−Copper(I)-Catalyzed Asymmetric Allylic Arylation of Aliphatic Allylic Bromides: Steric and Electronic Effects on γ-Selectivity
作者:Khalid B. Selim、Hirotsugu Nakanishi、Yasumasa Matsumoto、Yasutomo Yamamoto、Ken-ichi Yamada、Kiyoshi Tomioka
DOI:10.1021/jo102386s
日期:2011.3.4
sterically tuned to improve γ-selectivity in copper(I)-catalyzed asymmetric allylic arylation of aliphatic allylic bromides with several aryl Grignardreagents. High γ-selectivity was realized when either the aryl group of the Grignardreagent or the aryl group on the N-substituent of the carbene ligand was electron-deficient or when either the carbene ligand or allylic bromide was bulky. The results indicated