温和条件下Pd/π-酸配体催化的芳基碘化物和烷基铟试剂的交叉偶联反应

Pd/π-Acidic Ligand Catalyzed ArI and Alkyl-In Cross-Coupling Reactions under Mild Conditions

过渡金属催化的偶联反应是构建C—C键的重要途径.目前主要的催化剂为钯络合物,且对于Csp2-Csp2报道的是最多的,而Csp3相关成键的报道则相对少一些,主要是因为其涉及的还原消除较慢.我们曾发现π-酸类配体可以很好地促进Csp3-Pd-Csp2的还原消除,这对于Csp3相关的成键具有重要意义.报道了以膦烯烃、双烯化合物等π-酸化合物作为配体时,在温和条件下高选择性地实现了钯催化的芳基碘化物和烷基铟试剂的交叉偶联反应,构建Csp3-ArCsp2键.其中伯碳和仲碳的烷基铟试剂均可以很好的兼容;另外,进一步的研究表明,反应可以在敞口的条件下进行,对水和氧气可以兼容,并可以得到较高的产率.

Transition metal-catalyzed coupling reaction is an important approach to form C--C bond, in which palladium is the most popularly used catalyst. Up to now, the formation of Csp2-Csp2 has been widely reported in the presence of palla- dium catalysts. However, Cspa-related bond formations are relatively less demonstrated owing to the slow reductive elimina- tion of the corresponding Pd species. We have reported that n-acidic ligand could promote the reductive elimination of cspa-pd-Csp2, which is significant to construct Csp3-C bond. In this comunication, with Pd/n-acidic ligand as the catalyst, ArI and alkylindium reagents could be coupled together under mild conditions in high selectivity to form Csp2-ArCsp3 bond. Primary and secondary alkylindium could be tolerated. Moreover, further studies indicated that the reaction could be per- formed well when the reactions were open to air, suggesting that the reaciton was insensitive towards moisture and oxygen.