Enantioselective Addition of Boronates to Chromene Acetals Catalyzed by a Chiral Brønsted Acid/Lewis Acid System
作者:Philip N. Moquist、Tomohiro Kodama、Scott E. Schaus
DOI:10.1002/anie.201003469
日期:2010.9.17
Chiral α,β‐dihydroxy carboxylic acids catalyze the enantioselectiveaddition of alkenyl and aryl boronates to chromene acetals. The optimal carboxylic acid is the easily available tartaric acid amide shown in the scheme. Spectroscopic and kinetic mechanistic studies demonstrate that an exchange process generates a reactive dioxoborolane intermediate leading to enantioselectiveaddition to the pyrylium
Organocatalytic Enantioselective Oxidative CH Alkenylation and Arylation of<i>N</i>-Carbamoyl Tetrahydropyridines and Tetrahydro-β-carbolines
作者:Xigong Liu、Zhilin Meng、Chengkun Li、Hongxiang Lou、Lei Liu
DOI:10.1002/anie.201500703
日期:2015.5.11
The first organocatalyticenantioselectiveCHalkenylation and arylation reactions of N‐carbamoyl tetrahydropyridines and tetrahydro‐β‐carbolines (THCs) are described. The metal‐free processes represent an efficient and straightforward approach to a variety of structurally and electronically diverse α‐substituted tetrahydropyridines and THCs in good yields with excellent regio‐ and enantioselectivities