In 2019,ACS Catalysis included an article by Wang, Quannan; Chen, Rongjun; Lou, Jiang; Zhang, Dong H.; Zhou, Yong-Gui; Yu, Zhengkun. Quality Control of Methyltriphenylphosphonium bromide. The article was titled 《Highly Regioselective C-H Alkylation of Alkenes Through an Aryl to Vinyl 1,4-Palladium Migration/C-C Cleavage Cascade》. The information in the text is summarized as follows:
Palladium-catalyzed C-H alkylation of gem-disubstituted ethylenes has been efficiently achieved with cyclobutanols as the coupling partners through an aryl to vinyl 1,4-palladium migration/ring-opening C-C cleavage cascade, giving trisubstituted alkenes in high yields. The protocol features good regioselectivity, high yields, broad substrate scopes, and good functional group tolerance. The mechanistic studies implicate that the cross-coupling reaction occurs via oxidative addition, 1,4-palladium migration, ring-opening C-C cleavage, and reductive elimination. DFT calculations have revealed that the high efficiency of the protocol is attributed to the thermodynamically favored 1,4-palladium migration assisted by 2-fluorophenol. In the experimental materials used by the author, we found Methyltriphenylphosphonium bromide(cas: 1779-49-3Quality Control of Methyltriphenylphosphonium bromide)
Methyltriphenylphosphonium bromide(cas: 1779-49-3) is used for methylenation through the Wittig reaction. It is utilized in the synthesis of an enyne and 9-isopropenyl -phenanthrene by using sodium amide as reagent. Quality Control of Methyltriphenylphosphonium bromide
Referemce:
Bromide – Wikipedia,
bromide – Wiktionary