AN EFFICIENT, ONE-POT SYNTHESIS OF 1,3-THIAZINES AND 1,2,3,5-THIATRIAZINES FROM N-(TRIMETHYLSILYL)IMINES VIA [4-CYCLOADDITION OF 1-THIA-3-AZADIENES(2])
J. Barluenga et al., AN EFFICIENT, ONE-POT SYNTHESIS OF 1,3-THIAZINES AND 1,2,3,5-THIATRIAZINES FROM N-(TRIMETHYLSILYL)IMINES VIA [4-CYCLOADDITION OF 1-THIA-3-AZADIENES(2]), Synthesis, (8), 1995, pp. 985-988
The [4 + 2] cycloaddition reaction of 2-amino-1-thia-3-azabutadienes 2
, formed in situ from N-(trimethylsilyl)imines 1 and phenyl isothiocya
nate, towards electron-poor dienophiles is described. The process is a
pplied to a number of carbo- and heterodienophiles, allowing the regio
selective formation of the cycloadducts 3-7 with complete endo-stereos
electivity.