Lewis Base Activation of Silyl Acetals: Iridium-Catalyzed Reductive Horner–Wadsworth–Emmons Olefination
作者:Udaya Sree Dakarapu、Apparao Bokka、Parham Asgari、Gabriela Trog、Yuanda Hua、Hiep H. Nguyen、Nawal Rahman、Junha Jeon
DOI:10.1021/acs.orglett.5b02901
日期:2015.12.4
A Lewis base promoted deprotonative pronucleophile addition to silyl acetals has been developed and applied to the iridium-catalyzed reductive Horner–Wadsworth–Emmons (HWE) olefination of esters and the chemoselective reduction of the resulting enoates. Lewis base activation of silyl acetals generates putative pentacoordinate silicate acetals, which fragment into aldehydes, silanes, and alkoxides in
已经开发了路易斯碱促进的除甲硅烷基乙缩醛外的质子化原核亲核试剂,并将其应用于铱催化的酯的霍纳-沃兹沃斯-埃蒙斯(HWE)还原性烯化反应以及所得烯酸酯的化学选择性还原。甲硅烷基乙缩醛的路易斯碱活化生成推定的五配位硅酸酯乙缩醛,其原位分解为醛,硅烷和醇盐。膦酸酯的随后去质子化金属化,然后与醛进行HWE,提供烯酸酯。该操作方便,机制独特的方案可在室温下在单个容器中将传统上具有挑战性的芳基,烯基和炔基酯转化为均一的烯酸酯。