An efficient, one-pot synthesis of 1,3-thiazines and 1,2,3,5-thiatriazines from N-(trimethylsilyl)imines via [4 + 2] cycloaddition of 1-thia-3-azadienes

Article abstract of DOI:10.1055/s-1995-4033

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.