Centre for Synthesis and Chemical Biology, School of Chemistry, University of Dublin, Trinity College, Dublin 2, Ireland.
Org Lett. 2010 Feb 5;12(3):608-11. doi: 10.1021/ol902816w.
An investigation into the poor activity of sulfides as catalysts for sulfonium-ylide-mediated methylene transfer to aldehydes has indicated that ylide formation is the problematic catalytic cycle step. Alkylation with traditional electrophiles does not proceed with sufficient efficiency to allow the sulfide to be used catalytically. Methyl triflate rapidly alkylates cyclic thiolanes under mild conditions, allowing their use in efficient aldehyde epoxidation reactions (in conjunction with phosphazene bases) at loadings as low as 10 mol %.
硫化物作为亚磺酰基叶立德介导的亚甲基转移到醛的催化剂活性差的研究表明，叶立德的形成是有问题的催化循环步骤。用传统的亲电试剂进行烷基化反应的效率不够高，无法使硫化物进行催化。三氟甲磺酸甲酯在温和条件下迅速烷基化环硫烷，允许它们在低至 10mol%的负载量下与磷杂环戊二烯碱一起用于高效醛环氧化反应。
