Chemoselective bond activation by unidirectional and asynchronous PCET using ketone photoredox catalysts
作者:Rui Sun、Serge Ruccolo、Daniel L. Nascimento、Yangzhong Qin、Nathaniel Hibbert、Daniel G. Nocera
DOI:10.1039/d3sc04362b
日期:——
The triplet excited states of ketones are found to effect selective H-atom abstraction from strong amide N–H bonds in the presence of weaker C–H bonds through a proton-coupled electron transfer (PCET) pathway. This chemoselectivity, which results from differences in ionization energies (IEs) between functional groups rather than bond dissociation energies (BDEs) arises from the asynchronicity between
研究发现,酮的三重激发态可通过质子耦合电子转移 (PCET) 途径,在较弱的 C-H 键存在的情况下,选择性地从强酰胺 N-H 键中夺取 H 原子。这种化学选择性是由于官能团之间电离能 (IE) 的差异而不是键解离能 (BDE) 的差异而产生的,这是由于 PCET 过程中电子和质子转移之间的异步性引起的。我们展示了如何利用这一策略来实现烯烃的分子内反马尔可夫尼科夫氢酰胺化,以使用樟脑醌作为廉价且可持续的光催化剂形成内酰胺。