A, jS-unsaturated imines

A related reaction with a,jS-unsaturated imines allowed the one-pot synthesis of y-lactams [17] (Eq. 12). 

The cyclocarbonylation of a,jS-unsaturated imines 54 also gave five-membered lactams 55 or 56 with or without 57 depending on the substitution patterns of the starting materials (Eq. 26) [40]. Such a useful [4+1] cycloaddition was applied to a cyclic imine 58 conjugated with a cyclohexenyl group to afford an interesting aza-tricycle 59 in 65% yield (Eq. 27). In the presence of an alkene such as ethylene, norbornene, and vinyltrimethylsilane, a similar cyclocarbonylation of a,unsaturated imines 60 gave rise to a-alkylated j8,y-unsaturated lactam 61 in various yields (Eq. 28) [41,42]. Several plausible mechanisms are proposed for the formation of 61, but the elucidation of the entire mechanism calls for further work. 

The aza-Michael reaction of ammonia, aliphatic, aromatic and optically active amines to a,jS-unsaturated imines (393) derived from a-aminopho-sphonates, afforded a-dehydroaminophosphonates (394) with a y-stereogenic... 

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