Catalytic Asymmetric Conjugate Addition of α-Cyanoketones for the Construction of a Quaternary Stereogenic Center

The catalytic asymmetric conjugate addition of α-cyanoketone pronucleophiles to vinyl ketones promoted by a Y/1 catalyst is described. High enantioselectivity was observed for a range of aromatic vinyl ketones, providing 1,5-dicarbonyl compounds bearing an all-carbon quaternary stereogenic center. The product was successfully converted to a spiro-piperidine entity and a bicyclo[3.3.0]octane framework through either the reduction of nitrile or intramolecular pinacol coupling.

本研究报道了由Y/1催化剂（Y/1 catalyst）介导的α-氰酮前亲核试剂（α-cyanoketone pronucleophiles）与乙烯基酮的催化不对称共轭加成反应。针对一系列芳香族乙烯基酮，该反应展现出优异的对映选择性，可得到带有全碳季碳手性中心（all-carbon quaternary stereogenic center）的1,5-二羰基化合物。所得产物可通过腈基还原或分子内频哪醇偶联反应，分别转化为螺哌啶（spiro-piperidine）结构单元与双环[3.3.0]辛烷（bicyclo[3.3.0]octane）骨架。