Tandem Chemoselective 1,2-/1,4-Migration of the Thio Group in Keto Thioesters: An Efficient Approach to Substituted Butenolides
作者:Kanchan Mal、Sandip Naskar、Shovan Kumar Sen、Ramalingam Natarajan、Indrajit Das
DOI:10.1002/adsc.201600640
日期:2016.10.20
We report herein an efficient and mechanistically unique tandem chemoselective 1,2‐/1,4‐migration of the thio group in keto thioesters that provides substituted butenolides in moderate to excellent yields. Thus, α‐keto thioesters in the presence of stabilized phosphonate carbanions undergo tandem 1,2‐sulfur migration; whereas 1,4‐migration of the thio group has been achieved with the same thioesters
我们在此报告了酮基硫代酯中硫基团的高效且机械独特的串联化学选择性1,2- / 1,4-迁移,该酯基团可提供中等至极高收率的取代丁烯内酯。因此,在稳定的膦酸酯碳负离子存在下,α-酮基硫代酯会经历1,2-硫的串联迁移。而硫基的1,4-迁移已经用相同的硫酯与维悌希试剂,接着BF处理后已经达到3 ⋅OEt 2催化的串联反应。交叉实验和中间体的分离揭示了这两种转化的逐步机理。