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.
Chiral Phosphoric Acid Catalyzed Enantioselective Transfer Hydrogenation of ortho-Hydroxybenzophenone NH Ketimines and Applications
作者:Thanh Binh Nguyen、Qian Wang、Françoise Guéritte
DOI:10.1002/chem.201101694
日期:2011.8.22
Unprotected synthesis: The first enantioselective chiral phosphoric acid catalyzed transferhydrogenation of unprotected ortho‐hydroxybenzophenone NH imines by using a Hantzsch ester as the hydrogen source afforded the corresponding chiral N,O‐unprotected ortho‐hydroxydiarylmethylamines in high yields with excellent enantioselectivities (see scheme).