Cobalt-Catalyzed Highly Regio- and Stereoselective Intermolecular Reductive Coupling of Alkynes with Conjugated Alkenes
作者:Chun-Chih Wang、Pao-Shun Lin、Chien-Hong Cheng
DOI:10.1021/ja026543l
日期:2002.8.1
smoothly in acetonitrile to give the corresponding reductive coupling products (R1HC=CR2CH2CH2R, 3a-j) in fair to excellent yields. This reductive coupling is highly regio- and stereoselective; only one isomer was observed for each reaction. The results of an isotope-labeling experiment using D2O (99%) to replace normal water for the reductive coupling of vinyl phenyl sulfone 2c with alkyne 1a revealed that
在Co(PPh3)2I2、PPh3、水和锌粉存在下,炔烃的反应(R1CCR2:R1=Ph,R2=Me(1a);R1=Ph,R2=Ph(1b);R1=Et , R2 = Et (1c); R1 = Ph, R2 = (CH2)3OH (1d); R1 = CO2Et, R2 = Ph (1e); R1 = CO2Me, R2 = (CH2)4CH3 (1f); R1 = CO2Et , R2 = SiMe3 (1g)) 与具有吸电子取代基的烯烃 (CH2=CHR: R = CO2Bu (2a), CN (2b), SO2Ph (2c) 和 CO2Me (2d)) 在乙腈中顺利进行得到相应的还原偶联产物 (R1HC=CR2CH2CH2R, 3a-j) 的产率一般到极好。这种还原耦合具有高度的区域选择性和立体选择性;每个反应仅观察到一种异构体。使用 D2O (99%) 代替普通水进行乙烯基苯砜 2c