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.
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
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).
Direct enantioseparation of diarylmethylamines with an ortho-hydroxy group via diastereomeric salt formation and their application to the enantioselective addition reaction of diethylzinc
Two chiral diarylmethylamines with a phenolic hydroxy group at their ortho positions (1c and 1d) were synthesized, and their direct enantioseparationviadiastereomericsaltformation was investigated. Crystallographic analyses of the diastereomeric salts involving 1c were conducted: water molecules incorporated in the space played an important role in chiral recognition. Enantiopure 1 were applied