Rh-catalyzed asymmetric transfer hydrogenation. This transformation allowed the reduction of both the C═C and C═O bonds and the formation of two stereocenters in high yields with excellent levels of diastereo- and enantioselectivities (up to >99:1 dr, up to >99% ee) in a single step through a dynamic kinetic resolution process using a low catalyst loading and HCO2H/DABCO as the hydrogen source.
通过Rh催化的不对称转移氢化反应,可以直接从(E)-3-亚苄基-苯并二氢吡喃酮中获得对映异构体富集的顺式-3-苄基-苯并二氢苯并二氢苯并二氢吡喃酚。这种转变可以降低C═C和C═O键,并以高收率形成两个立构中心,且非对映和对映选择性极好(高达> 99:1 dr,高达> 99%ee)。通过动态动力学拆分过程的一个步骤,即使用低催化剂负载量和HCO 2 H / DABCO作为氢源。
Ketone–Olefin Coupling of Aliphatic and Aromatic Carbonyls Catalyzed by Excited-State Acridine Radicals
作者:Nicholas J. Venditto、Yiyang S. Liang、Roukaya K. El Mokadem、David A. Nicewicz
DOI:10.1021/jacs.2c04822
日期:2022.7.6
easily reducible aromaticcarbonyl compounds. Herein, we describe a mild, metal-free ketone–olefin coupling reaction using an excited-state acridine radical super reductant as a photoredox catalyst. We demonstrate both intramolecular and intermolecular ketone–olefin couplings of aliphatic and aromaticketones and aldehydes. Mechanistic evidence is also presented supporting an “olefin first” ketone–olefin