Asymmetric synthesis of 4H-1,3-oxazines: enantioselective reductive cyclization of N-acylated β-amino enones with trichlorosilane catalyzed by chiral Lewis bases
作者:Masaharu Sugiura、Mako Kumahara、Makoto Nakajima
DOI:10.1039/b905102c
日期:——
N-Acylated beta-amino enones reductivelycyclize by treatment with trichlorosilane and a chiral Lewis base catalyst to afford optically active 4H-1,3-oxazines, which can be transformed to other chiral compounds without racemization.
A series of opticallypure β-amino ketones have been synthesized in high enantioselectivities (ee > 99%) by Rh-DuanPhos-catalyzed asymmetric hydrogenation of readily prepared β-keto enamides. Further reduction of these β-amino ketones with hydrogen and Pd/C leads to the formation of a variety of protected enantiomerically pure γ-aryl amines (ee > 99%), which are key building blocks in many bioactive
2,3-BISPHOSPHINOPYRAZINE DERIVATIVE, METHOD FOR PRODUCING SAME, TRANSITION METAL COMPLEX, ASYMMETRIC CATALYST, AND METHOD FOR PRODUCING ORGANIC BORON COMPOUND
申请人:Nippon Chemical Industrial Co., Ltd.
公开号:US20210047351A1
公开(公告)日:2021-02-18
Provided is a 2,3-bisphosphinopyrazine derivative represented by the following general formula (1), wherein R
1
, R
2
, R
3
, and R
4
represent an optionally substituted straight-chain or branched alkyl group having 1 to 10 carbon atoms, an optionally substituted cycloalkyl group, an optionally substituted adamantyl group, or an optionally substituted phenyl group, R
5
represents an optionally substituted alkyl group having 1 to 10 carbon atoms or an optionally substituted phenyl group, each R
5
may be the same group or a different group, R
6
represents a monovalent substituent, n denotes an integer of 0 to