E. Rossi et al., [4-(4-METHYLPHENYL) AND 1-BENZYL-1,3-DIAZA-1,3-BUTADIENES WITH KETENES(2]CYCLOADDITION AND [2+2]CYCLOADDITION REACTIONS OF 1), Tetrahedron, 53(41), 1997, pp. 14107-14114
[4+2] and [2+2] cycloaddition reactions of 1-(4-methylphenyl) and L-be
nzyl-1,3-diaza-1,3-butadienes with monophenyl, diphenyl, monochloro an
d ethoxycarbonylketenes are described. The mechanism of these reaction
s is also discussed. (C) 1997 Elsevier Science Ltd.