Photochemical Cleavage of Benzylic C–O Bond Facilitated by an <i>Ortho</i> or <i>Meta</i> Amino Group
作者:Xiong Ding、Pengfei Wang
DOI:10.1021/acs.joc.7b00927
日期:2017.7.21
The excited state meta effect, also known as the meta-ortho effect, results from selective electron transmission from an electron-donating group to the meta and ortho sites on an aromatic ring in its first excited singlet state. This effect facilitates photochemical cleavage of benzylic C-O or C-N bond to release the corresponding alcohol, carboxylic acid, or amine when an electron-donating amino group
激发态的间位效应,也称为间位邻效应,是由于在给定的第一个激发单重态下,电子从供电子基团选择性转移到芳香环上的间位和邻位。如我们最近使用3-二乙基氨基苄基(DEABn)的研究所示,当给电子的氨基位于间位时,这种作用促进了苄基CO或CN键的光化学裂解,从而释放出相应的醇,羧酸或胺。基团作为有效的光不稳定保护基团(PPG)。在本文中,我们证明邻氨基也可以促进苄基CO键裂解以释放醇或羧酸。但是,间位的氨基会导致PPG具有更好的整体化学和光化学性质。