Cp<sub>2</sub>ZrMeCl: A Reagent for Asymmetric Methyl Addition
作者:Kilian Garrec、Stephen P. Fletcher
DOI:10.1021/acs.orglett.6b01829
日期:2016.8.5
The use of Cp2ZrMeCl is described as a source of nucleophilicmethyl in asymmetric catalysis. This easily prepared reagent is bench stable, weighable in air, and generally useful in highly enantioselective copper-catalyzed addition reactions at room temperature. Methyl is successfully (generally >90% ee) added in 1,4-additions to cyclic and acyclic α,β-unsaturated ketones to provide tertiary and quaternary
The present invention provides a sterol derivative or a pharmaceutically acceptable salt thereof having an activity to promote proliferation of neural stem cells. Namely, the present invention provides a sterol derivative represented by the general formula (I) (wherein Y represents optionally substituted lower alkyl or the like; X
a
and X
b
are the same or different, and represent a bond or the like; R
1
, R
2
, R
3
, R
4
, R
7
and R
8
are the same or different, and represent a hydrogen atom or the like; R
5
and R
6
are the same or different, and represent a hydrogen atom or the like; R
9
represents a hydrogen atom or the like; R
10
and R
11
together represent a bond or the like; and R
12
represents a hydrogen atom or the like) or a pharmaceutically acceptable salt thereof.