Cooperative Titanocene and Phosphine Catalysis: Accelerated C–X Activation for the Generation of Reactive Organometallics
作者:Lauren M. Fleury、Andrew D. Kosal、James T. Masters、Brandon L. Ashfeld
DOI:10.1021/jo301726v
日期:2013.1.18
transmetalation approach toward the generation of Grignard and organozinc reagents mediated by a titanocene catalyst. This method enables the metalation of functionalized substrates without loss of functional group compatibility. Allyl zinc reagents and allyl, vinyl, and alkyl Grignard reagents were generated in situ and used in the addition to carbonyl substrates to provide the corresponding carbinols in yields
本文介绍的研究描述了一种通过钛茂催化剂介导的格氏试剂和有机锌试剂的还原性过渡金属化方法。该方法能够在不损失官能团相容性的情况下金属化官能化的基材。烯丙基锌试剂和烯丙基,乙烯基和烷基格氏试剂原位生成,并用于加成羰基底物,以提供相应的甲醇,收率高达99%。研究发现,膦配体可有效地促进还原性金属转移反应,从而在低至−40°C的温度下实现C–X键的金属化。在手性二胺和氨基醇的存在下进行反应导致醛的对映选择性烯丙基化。