Cobalt-Catalyzed Asymmetric Hydrogenation of 1,1-Diarylethenes
作者:Jianhui Chen、Chenhui Chen、Chonglei Ji、Zhan Lu
DOI:10.1021/acs.orglett.6b00453
日期:2016.4.1
Highlyenantioselective cobalt-catalyzed hydrogenation of 1,1-diarylethenes was developed by using bench-stable chiral oxazoline iminopyridine–cobalt complexes as precatalysts. A unique o-chloride effect was observed to achieve high enantioselectivity. Easy removal as well as further transformations of the chloro group make this protocol a potentially useful alternative to synthesize various chiral
Asymmetric Transfer Hydrogenation of <i>o</i>-Hydroxyphenyl Ketones: Utilizing Directing Effects That Optimize the Asymmetric Synthesis of Challenging Alcohols
作者:Ye Zheng、Guy J. Clarkson、Martin Wills
DOI:10.1021/acs.orglett.0c01213
日期:2020.5.1
A systematic range of o-hydroxyphenyl ketones were reduced under asymmetrictransferhydrogenation conditions using the C3-tethered catalyst 2. Two directing effects, i.e., an o-hydroxyphenyl coupled to a bulky aromatic on the opposite side of the ketone substrate, combine in a matched manner to deliver reduction products with very high enantiomeric excess.