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
application of binaphthyl-stabilized palladium nanoparticles (Bin-PdNPs) with chiral modifiers in asymmetric hydrogenation of N-heteroaromatics is revealed. With an appropriate ratio of R-BINAP/Bin-PdNPs used, the pre-prepared chiral nanocatalyst achieves asymmetric hydrogenations of 2-substituted quinolines with good to excellent yields and moderate enantioselectivities, which showed superior catalytic properties
We have developed a highly efficient and practical strategy for the kinetic resolution of indoline derivatives, involving a chiral Brønstedacid-catalyzed iminium ion formation and asymmetric transfer hydrogenation cascade process. The kinetic resolution allows the synthesis of 2-substituted N-benzylindolines in good yields with moderate to excellent enantioselectivities.
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.