[GRAPHICS]The diphenylmethyl amino protecting group can be efficiently removed by initial oxidation of the amine to an imine by 2,3-dichloro-5,6-dicyanobenzoquinone. The resulting imine can then be easily hydrolyzed under mildly acidic conditions. This method is particularly well suited for the preparation of alpha-amino phosphinates and alpha-amino phosphonates.
[GRAPHICS]The diphenylmethyl amino protecting group can be efficiently removed by initial oxidation of the amine to an imine by 2,3-dichloro-5,6-dicyanobenzoquinone. The resulting imine can then be easily hydrolyzed under mildly acidic conditions. This method is particularly well suited for the preparation of alpha-amino phosphinates and alpha-amino phosphonates.
An enantioselective palladium-catalyzed C(sp(2))-H carbamoylation for the preparation of chiral iso-indolines was described for the first time. With chiral monophosphorus ligand (R)-AntPhos as the ligand, a series of chiral isoindolines were prepared from diarylmethyl carbamoyl chlorides in excellent yields and enantioselectivities with the palladium loading as low as 1 mol%. Initial mechanistic studies indicated the asymmetric cyclization catalyzed a palladium species with a single chiral monophosphorus ligand. (C) 2019 Elsevier Ltd. All rights reserved.
Oxidative Deprotection of Diphenylmethylamines
作者:Peter B. Sampson、John F. Honek
DOI:10.1021/ol990956i
日期:1999.11.1
[GRAPHICS]The diphenylmethyl amino protecting group can be efficiently removed by initial oxidation of the amine to an imine by 2,3-dichloro-5,6-dicyanobenzoquinone. The resulting imine can then be easily hydrolyzed under mildly acidic conditions. This method is particularly well suited for the preparation of alpha-amino phosphinates and alpha-amino phosphonates.