Regio- and Stereoselective Carboindation of Internal Alkynyl Ethers with Organosilicon or -stannane Nucleophiles
作者:Kyoungmin Kang、Yoshihiro Nishimoto、Makoto Yasuda
DOI:10.1021/acs.joc.9b01505
日期:2019.11.1
and reduces the activation energy. Many types of carbon nucleophiles such as silyl ketene acetals, silyl ketene imines, a silyl cyanide, an alkynyl stannane, and an allylic stannane were applicable to the present reaction system to give highly functionalized metalated enol ethers (β-alkoxyalkenylindiums). The prepared β-alkoxyalkenylindiums were transformed to various functionalized tetrasubstituted
我们使用InI3和有机硅或-锡烷亲核试剂合成(Z)-β-烷氧基烯基铟,实现了末端和内部炔基醚的区域和立体选择性碳氢化。通过(Z)-β-烷氧基烯基铟产物的X射线衍射分析证实,碳金属化区域和立体选择性地以抗加成方式进行。与计算炔基醚的碳类似物并行地进行了关于炔基醚的碳键化以阐明烷氧基的作用的理论计算。碳偶合反应的反应曲线和计算数据表明,烷氧基增强了InI3和炔烃部分之间的相互作用,并降低了活化能。许多类型的碳亲核试剂,例如甲硅烷基乙烯酮缩醛,甲硅烷基乙烯酮亚胺,甲硅烷基氰化物,炔基锡烷和烯丙基锡烷可用于本反应体系,以得到高度官能化的金属化烯醇醚(β-烷氧基烯基铟)。通过碘化然后铃木偶联将制备的β-烷氧基烯基铟转化成各种官能化的四取代的烯醇醚。含有酚醚部分的七元环化合物的合成是使用包括本发明的立体选择性碳indindation的顺序过程完成的。