Highly efficient and regiospecific photocyclization of 2,2′-diacyl bixanthenylidenes
作者:Mao Mao、Qing-Qing Wu、Ming-Guang Ren、Qin-Hua Song
DOI:10.1039/c1ob05072a
日期:——
In contrast to the reversiblephotochemistry of the 2,2′-substituted bixanthenylidenes (1a–f), the photocyclization of 2,2′-diacyl bixanthenylidenes (1g–j) reveals an irreversible process where the initial cyclic intermediate C(E) can undergo a rapid [1,11] hydrogen shift to form stable isomer C′(E) in a degassed solution, which cannot revert to the starting compound, so giving a highly efficient and