Surmounting Byproduct Inhibition in an Intermolecular Catalytic Asymmetric Alkene Bromoesterification Reaction as Revealed by Kinetic Profiling
作者:D. Christopher Braddock、Ben M. J. Lancaster、Christopher J. Tighe、Andrew J. P. White
DOI:10.1021/acs.joc.3c00672
日期:2023.7.7
Kinetic profiling has shown that a (DHQD)2PHAL-catalyzed intermolecular asymmetric alkene bromoesterification reaction is inhibited by primary amides, imides, hydantoins, and secondary cyclic amides, which are byproducts of common stoichiometric bromenium ion sources. Two approaches to resolving the inhibition are presented, enabling the (DHQD)2PHAL loading to be dropped from 10 to 1 mol % while maintaining
动力学分析表明,(DHQD) 2 PHAL 催化的分子间不对称烯烃溴酯化反应受到伯酰胺、酰亚胺、乙内酰脲和仲环酰胺的抑制,这些都是常见化学计量溴离子源的副产物。提出了两种解决抑制问题的方法,使 (DHQD) 2 PHAL 负载量从 10 mol% 降至 1 mol%,同时在 8 小时或更短时间内保持高溴酯转化率。反复反应后重结晶使得仅使用 1 mol% (DHQD) 2 PHAL 即可合成纯手性溴萘甲酸酯。