The [4+2] cycloaddition reaction of 2-amino-1-thia-3-azabutadienes 2, formed in situ from N-(trimethylsilyl)imines 1 and phenyl isothiocyanate, towards electron-poor dienophiles is described. The process is applied to a number of carbo- and heterodienophiles, allowing the regioselective formation of the cycloadducts 3-7 with complete endo-stereoselectivity.
介绍了由 N-(三甲基
硅基)
亚胺 1 和异
硫氰酸苯酯原位生成的 2-
氨基-1-
硫杂-3-氮杂
丁二烯 2 与贫电子二烯烃的 [4+2] 环加成反应。该过程适用于多种碳二烯烃和杂二烯烃,能够以完全的内-立体选择性形成环加成物 3-7。