posted on 2003-01-09, 00:00authored byShengJian Li, R. Karl Dieter
α-(N-Carbamoylalkyl)cuprates couple with enol triflates derived from carbocyclic and heterocyclic
(i.e., piperidinones) β-keto esters. Product yields are higher with the alkyl(cyano)cuprates [i.e., RCu(CN)Li, 56−93%] than with the dialkylcuprate reagents (i.e., R2CuLi·LiCN). An enol nonaflate works
as well as the corresponding enol triflate. A facile synthetic route to γ-amino α,β-enoates not readily
prepared from γ-keto-α,β-enoates is thus established. The γ-amino-α,β-enoates, available via N-Boc
deprotection, can be cyclized to annulated pyrrolin-2-ones.