Department of Chemistry, University of Texas at Austin , Austin, Texas 78712, United States.
J Am Chem Soc. 2017 May 24;139(20):6847-6850. doi: 10.1021/jacs.7b03371. Epub 2017 May 10.
Under the conditions of nickel(0) catalysis, enantiomerically enriched vinyl dioxanones engage boroxines or B(pin) in stereospecific cross-coupling to form diverse tetrasubstituted cyclopropanes bearing all-carbon quaternary stereocenters. The collective data corroborate a mechanism involving nickel(0)-mediated benzylic oxidative addition with inversion of stereochemistry followed by reversible olefin insertion to form a (cyclopropylcarbinyl)nickel complex, which upon reductive elimination releases the cyclopropane.
在镍(0)催化条件下，对映体富集的乙烯基二恶烷与硼酸酯或 B(pin)发生立体特异性交叉偶联，形成多种含有全碳季立体中心的四取代环丙烷。这些数据证实了一个涉及镍(0)介导的苄基氧化加成和立体化学反转的反应机制，然后是可逆的烯烃插入形成(环丙基碳鎓)镍配合物，该配合物通过还原消除释放环丙烷。
