A new chiral Brønsted acid, generated in situ from a chiral phosphoric acid boron (CPAB) complex and water, was successfully applied to asymmetric indole reduction. This "designer acid catalyst", which is more acidic than TsOH as suggested by DFT calculations, allows the unprecedented direct asymmetricreduction of C2-aryl-substituted N-unprotected indoles and features good to excellent enantioselectivities
Chiral Phosphoric Acid Catalyzed Kinetic Resolution of Indolines Based on a Self-Redox Reaction
作者:Kodai Saito、Takahiko Akiyama
DOI:10.1002/anie.201510692
日期:2016.2.24
A strategy for oxidative kineticresolution of racemic indolines was developed, employing salicylaldehyde derivative as the pre‐resolving reagent and chiral phosphoric acid as the catalyst. The iminium intermediate, formed by the condensation reaction of an enantiomer of indoline with salicylaldehyde derivative, was hydrogenated by the same enantiomer of indoline to afford another enantiomer of indoline
Kinetic Resolution of Indolines by Pd-Catalyzed Asymmetric Allylic Amination
作者:Xue Long Hou、Bao Hui Zheng
DOI:10.1021/ol9002543
日期:2009.4.16
The kinetic resolution of indolines was realized via a Pd-catalyzed allylic substitution reaction by using Trost's chiral ligand L10, affording optically active indolines and N-allylated indolines in high yields and high enantioselectivities with an S factor up to 59, which provided the first example for the kinetic resolution of nucleophiles via a transition-metal-catalyzed allylic substitution reaction.