Three-component Oxytrifluoromethylation of Alkenes: Highly Efficient and Regioselective Difunctionalization of CC Bonds Mediated by Photoredox Catalysts
作者:Yusuke Yasu、Takashi Koike、Munetaka Akita
DOI:10.1002/anie.201205071
日期:2012.9.17
Here comes the sun: A facile vicinal difunctionalization of alkenes, oxytrifluoromethylation, was established by visible‐light‐driven photoredox catalysis. Judicious choice of the CF3 source is key. Nucleophiles such as water, alcohols, and carboxylic acids can be used in this highlyefficient (2–4 h) and regioselective (100 %) transformation using light‐emitting diode (LED) lamps and natural sunlight
The DIBAL reduction of 2-phenylethyl 3,3,3-trifluoro-2-methylpropionate 2 at −78 °C afforded the aluminum acetal 3, and this intermediate, on worming up to 0 °C, was found to slowly decompose into the corresponding aldehyde 4, which smoothly reacted with appropriate nucleophiles in a one-pot manner in good to excellent yields with up to 93% diastereoselectivity.
Manganese-Catalyzed Aerobic Oxytrifluoromethylation of Styrene Derivatives Using CF<sub>3</sub>SO<sub>2</sub>Na as the Trifluoromethyl Source
作者:Yi Yang、Yingle Liu、Yan Jiang、Yu Zhang、David A. Vicic
DOI:10.1021/acs.joc.5b00781
日期:2015.7.2
A mild and practical protocol for manganese-catalyzed aerobic oxytrifluoromethylation of olefinic bonds of styrene derivatives using CF3SO2Na (Langlois' reagent) as the CF3 source is described. A distinguishing feature of this method is the generation of trifluoromethyl radicals from CF3SO2Na using the simple manganese salt/O-2 system. The reaction proceeds under ambient conditions, free of added peroxide initiators, and provides moderate to good selectivities for alcohol versus ketone product.
Remarkable dependency of diastereoselectivity on the selection of hydride sources and Lewis acids in the reduction of 2-(trifluoromethyl)propiophenone