In 2019,Journal of the American Chemical Society included an article by Liu, Wen-Qiang; Lei, Tao; Zhou, Shuai; Yang, Xiu-Long; Li, Jian; Chen, Bin; Sivaguru, Jayaraman; Tung, Chen-Ho; Wu, Li-Zhu. Application In Synthesis of Methyltriphenylphosphonium bromide. The article was titled 《Cobaloxime Catalysis: Selective Synthesis of Alkenylphosphine Oxides under Visible Light》. The information in the text is summarized as follows:
Direct activation of H-phosphine oxide to react with an unsaturated C-C bond is a straightforward approach for accessing alkenylphosphine oxides, which shows significant applications in both synthetic and material fields. However, expensive metals and strong oxidants are typically required to realize the transformation. Here, the authors demonstrate the utility of earth-abundant cobaloxime to convert H-phosphine oxide into its reactive radical species under visible light irradiation The radical species thus generated can be used to functionalize alkenes and alkynes without any external photosensitizer and oxidant. The coupling with terminal alkene generates E-alkenylphosphine oxide with excellent chemo- and stereoselectivity. The reaction with terminal alkyne yields linear E-alkenylphosphine oxide via neutral radical addition, while addition with internal ones generates cyclic benzophosphine oxides and H. Mechanistic studies on radical trapping experiments, ESR studies, and spectroscopic measurements confirm the formation of phosphinoyl radical and Co intermediates that are from capturing the electron and proton eliminated from H-phosphine oxide. The highlight of the authors’ mechanistic study is the dual role played by cobaloxime, viz., both as the visible light absorber to activate the P(O)-H bond as well as a H transfer agent to influence the reaction pathway. This synergetic feature of the cobaloxime catalyst preforming multiple functions under ambient condition provides a convergent synthetic approach to vinylphosphine oxides directly from H-phosphine oxides and alkenes (or alkynes). After reading the article, we found that the author used Methyltriphenylphosphonium bromide(cas: 1779-49-3Application In Synthesis 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. Application In Synthesis of Methyltriphenylphosphonium bromide
Referemce:
Bromide – Wikipedia,
bromide – Wiktionary