Stereoselective Synthesis of (2Z)-2,4-Dienamides via NBS-Mediated Allyloxyl Addition-Claisen Rearrangement-Dehydrobromination Cascade Reaction of Ynsulfonamides.
An NBS-promoted allyloxyl addition-Claisen rearrangement-dehydrobromination cascade reaction has been developed. More than 20 substituted alkynylsulfonamides were reacted with allyl alcohols to generate (2Z)-2,4-dienamides in moderate to high yields. A mechanistic model has been proposed to account for the overall reaction sequence including the stereochemical outcome. Theoretical calculations suggested that a [3,3] sigmatropic rearrangement be the rate-limiting step.
†The State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou, 730000, China.
Runbo
R
Ding
†The State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou, 730000, China.
Yun
Y
Li
†The State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou, 730000, China.
Cheng
C
Tao
†The State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou, 730000, China.
Bin
B
Cheng
†The State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou, 730000, China.|‡Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300071, China.
Hongbin
H
Zhai