Exploiting the Imidazolium Effect in Base-free Ammonium Enolate Generation: Synthetic and Mechanistic Studies
作者:Claire M. Young、Daniel G. Stark、Thomas H. West、James E. Taylor、Andrew D. Smith
DOI:10.1002/anie.201608046
日期:2016.11.7
function as ammonium enolate precursors in the absence of base. Enantioselective Michael addition–cyclization reactions using different α,β‐unsaturated Michael acceptors have been performed to form dihydropyranones and dihydropyridinones with high stereoselectivity. Detailed mechanistic studies using RPKA have revealed the importance of the “imidazolium” effect in ammonium enolate formation and have highlighted
在没有碱的情况下,N-酰基咪唑和催化的异硫脲盐酸盐催化物起烯醇铵的前体作用。已经进行了使用不同的α,β-不饱和Michael受体的对映选择性Michael加成环化反应,以形成具有高立体选择性的二氢吡喃酮和二氢吡啶并酮。使用RPKA进行的详细机械研究揭示了“咪唑”效应在烯醇铵形成中的重要性,并强调了与传统碱介导方法的主要区别。