A Tunable Route to Prepare alpha,beta-Unsaturated Esters and alpha,beta-Unsaturated-gamma-Keto Esters through Copper-Catalyzed Coupling of Alkenyl Boronic Acids with Phosphorus Ylides

作者：Bi, Hong-Yan; Liu, Feng-Ping; Liang, Cui; Su, Gui-Fa^*; Mo, Dong-Liang^*

来源：Advanced Synthesis & Catalysis, 2018, 360(7): 1510-1516.

DOI：10.1002/adsc.201701640

• alkenyl boronic acids
• copper-catalysis
• cross-coupling
• phosphorus ylide
• -unsaturated ester

A tunable strategy to prepare ,-unsaturated esters and ,-unsaturated--keto esters in good to excellent yields was developed through copper-catalyzed oxidative coupling of phosphorus ylides with alkenyl boronic acids under mild conditions. The reaction without water afforded ,-unsaturated esters, ketones, and amides while ,-unsaturated--keto esters, 1,4-,-unsaturated diketones and ,-unsaturated--keto amides were obtained when using 5.0equiv. of water. H2O18 labeling experiments showed that water played an important role in the formation of ,-unsaturated--keto esters. A plausible formation mechanism for ,-unsaturated esters and ,-unsaturated--keto esters was proposed based on mechanistic studies. Phosphonium salts could also be used directly as coupling partners instead of phosphorus ylides. The reaction exhibited a broad substrate scope, good functional group tolerance, good regioselectivity, and diverse coupling products.

• 出版日期2018-4-3
• 单位广西师范大学