Synthesis of N-Allylideneamines and Their Use for the Double Nucleophilic Addition of Ketene Silyl (Thio)acetals and Trimethylsilyl Cyanide

N-Allylideneamines 1a,b were prepared from acrolein and diphenylethyl or trityl amine in the presence of Ti(OEt)₄. Double nucleophilic addition of various ketene silyl (thio)acetals and trimethylsilyl cyanide to these imines proceeded efficiently to give, after workup with TFA, homoglutamic acid derivatives 3 and valerolactam 5.