Tertiary and Quaternary Carbon Formation via Gallium-Catalyzed Nucleophilic Addition of Organoboronates to Cyclopropanes
作者:Truong N. Nguyen、Jeremy A. May
DOI:10.1021/acs.orglett.7b03349
日期:2018.1.5
via homoconjugate addition of organoboron nucleophiles to diester- and ketone-functionalized cyclopropanes. Electron donor group cyclopropane substituents were not needed, allowing electron-deficient aryl, alkenyl, alkyl, and hydrogen-substituted cyclopropanes to be used. The catalytic conditions were compatible with alkenyl, alkynyl, and aryl nucleophiles, including ortho-substituted aromatics, to
GaCl 3和(IPr)GaCl 3 / AgSbF 6通过将有机硼亲核试剂均相加成到二酯和酮官能化的环丙烷上而形成γ-叔碳和γ-季碳。不需要电子供体基团的环丙烷取代基,从而可以使用缺电子的芳基,烯基,烷基和氢取代的环丙烷。催化条件与烯基,炔基和芳基亲核试剂(包括邻位取代的芳族化合物)相容,以合成高度受阻的季碳。炔基亲核试剂形成取代的环戊烯。对照实验支持季碳中心形成中的中间碳正离子化。