Dynamic Kinetic Resolution of Allylic Sulfoxides by Rh-Catalyzed Hydrogenation: A Combined Theoretical and Experimental Mechanistic Study
作者:Peter K. Dornan、Kevin G. M. Kou、K. N. Houk、Vy M. Dong
DOI:10.1021/ja409824b
日期:2014.1.8
with catalytic asymmetric hydrogenation. The efficiency of our DKR was optimized by using low pressures of hydrogen gas to decrease the rate of hydrogenation relative to the rate of sigmatropic rearrangement. Kinetic studies reveal that the rhodium complex acts as a dual-role catalyst and accelerates the substrate racemization while catalyzing olefin hydrogenation. Scrambling experiments and theoretical
通过将 Mislow [2,3]-σ 重排与催化不对称氢化相结合,证明了烯丙基亚砜的动态动力学拆分 (DKR)。我们的 DKR 的效率通过使用低压氢气来降低相对于 σ 重排速率的氢化速率来优化。动力学研究表明,铑配合物可作为双重催化剂,在催化烯烃氢化的同时加速底物外消旋化。加扰实验和理论模型支持亚砜外消旋的新模式,该模式通过极性溶剂中的铑 π-烯丙基中间体发生。然而,在非极性溶剂中,底物外消旋主要是未催化的。