Improvements and Applications of the Transition Metal-Free Asymmetric Allylic Alkylation using Grignard Reagents and Magnesium Alanates
作者:David Grassi、Alexandre Alexakis
DOI:10.1002/adsc.201500495
日期:2015.10.12
Two new N-heterocyclic carbene (NHC) ligands have been synthesized and employed in the transition metal-free asymmetric allylic alkylation (AAA) mediated by Grignard reagents and magnesium alanates. The employment of these ligands showed high yields and improved regio- and enantioselectivity in the formation of tertiary and quaternary stereocenters. Moreover, the low catalyst loading (up to 0.3 mol%)
已经合成了两个新的N杂环卡宾(NHC)配体,并用于由格氏试剂和铝酸镁介导的无过渡金属的不对称烯丙基烷基化(AAA)。这些配体的使用在第三和第四立体中心的形成中显示出高产率并改善了区域和对映选择性。此外,这种改进方法的低催化剂负载量(最高0.3 mol%)和高可扩展性(最高10 mmol)为生物活性化合物和合成有价值的中间体提供了便捷的途径。