Stereoselective Synthesis of (2Z)-2,4-Dienamides via NBS-Mediated Allyloxyl Addition-Claisen Rearrangement-Dehydrobromination Cascade Reaction of Ynsulfonamides
Runbo Ding, Yun Li*, Cheng Tao, Bin Cheng and Hongbin Zhai*
*The State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou, 730000, China, Email: zhaihlzu.edu.cn, liyunlzu.edu.cn
R. Ding, Y. Li, C. Tao, B. Cheng, H. Zhai, Org. Lett., 2015, 17, 3994-3997.
DOI: 10.1021/acs.orglett.5b01859 (free Supporting Information)
see article for more reactions
In an NBS-promoted allyloxyl addition-Claisen rearrangement-dehydrobromination cascade reaction, more than 20 substituted alkynylsulfonamides were reacted with allyl alcohols to generate (2Z)-2,4-dienamides in good yields. Theoretical calculations suggested that a [3,3] sigmatropic rearrangement be the rate-limiting step.
see article for more examples