A mild and efficient one-pot visible light-induced method has been developed for the allylic oxidation. The oxidation of allylic systems has played a prominent role in this context as possibly the most widely applied C-H functionalization, owing to the utility of enones. The allylic C-H oxidation is relatively simple and predictable, even on a preparative scale, because active species generated at the allylic position are stabilized by the double bond.
Achieving Vinylic Selectivity in Mizoroki-Heck Reaction of Cyclic Olefins
作者:Xiaojin Wu、Yunpeng Lu、Hajime Hirao、Jianrong Steve Zhou
DOI:10.1002/chem.201204427
日期:2013.5.3
In Heck reactions of cyclicolefins, the products usually have aryl groups that end up at the allylic and/or homoallylic position. We herein report new selectivity that adds aryl groups to the vinylic position. Cyclicolefins of various ring size worked well. The desired isomers were produced by palladium–hydride‐catalyzed isomerization of the initial products. Thus, a specific catalyst must be used
An electrondonor–acceptorcomplex was utilized to generate alkoxy radicals from alcohols under mild conditions using visible light. This approach was combined with a hydroxybromination process to achieve the deconstructive functionalization of alkenes, leading to the production of geminal dibromides. Mechanistic investigations indicated the intermediacy of hypervalent iodine (III) compounds.