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).
Ruthenium‐Catalyzed Direct Asymmetric Reductive Amination of Diaryl and Sterically Hindered Ketones with Ammonium Salts and H
<sub>2</sub>
作者:Le' an Hu、Yao Zhang、Qing‐Wen Zhang、Qin Yin、Xumu Zhang
DOI:10.1002/anie.201915459
日期:2020.3.23
A Ru-catalyzed directasymmetric reductive amination of ortho-OH-substituted diaryl and sterically hindered ketones with ammonium salts is reported. This method represents a straightforward route toward the synthesis of synthetically useful chiral primary diarylmethylamines and sterically hindered benzylamines (up to 97 % yield, 93->99 % ee). Elaborations of the chiral amine products into bioactive