Inverse Electron-Demand Aza-Diels–Alder Reaction of α,β-Unsaturated Thioesters with In Situ-Generated 1,2-Diaza-1,3-dienes for the Synthesis of 1,3,4-Thiadiazines
作者:Li-Wen Shen、Yan-Ping Zhang、Yong You、Jian-Qiang Zhao、Zhen-Hua Wang、Wei-Cheng Yuan
DOI:10.1021/acs.joc.1c03072
日期:2022.3.18
electron-demand aza-Diels–Alder reaction of α,β-unsaturated thioesters with 1,2-diaza-1,3-dienes generated in situ from α-halogeno hydrazones was developed. With α,β-unsaturated thioesters as C═S dienophiles, the developed protocol enables the formation of diverse 3,6-dihydro-2H-1,3,4-thiadiazine derivatives in excellent yields. In the presence of lithium aluminum hydride, 3,6-dihydro-2H-1,3,4-thiadiazine
开发了α,β-不饱和硫酯与 α-卤代腙原位生成的 1,2-二氮杂-1,3-二烯的高度区域选择性逆电子需求氮杂-狄尔斯-阿尔德反应。以 α,β-不饱和硫酯作为 C=S 亲双烯体,所开发的方案能够以优异的收率形成多种 3,6-二氢-2 H -1,3,4-噻二嗪衍生物。在氢化铝锂的存在下,3,6-二氢-2 H -1,3,4-噻二嗪衍生物可以进一步转化为5,6-二氢-4 H -1,3,4-噻二嗪,收率良好。