Michael Addition and Alkylation of 2-Azaallyl Anions Derived from N-(1-Cyanoalkyl)imines, and Stereoselective Cyclization of Imine Esters or Ketones Leading to 1-Pyrrolines

Article abstract of DOI:10.1246/bcsj.60.3347

The 2-azaallyl anions derived from N-(1-cyanoalkyl)imines and DBU undergo Michael addition or alkylation to produce N-(1-alkylated 1-cyanoalkyl)imines.The Michael addition of some aryl-substituted imines are highly diastereoselective.The alkylated Michael adducts are converted into lactams through a hydrolysis and recyclization sequence.Base-induced cyclization furnishes 1-pyrroline through a cyclization and HCN elimination sequence.In the latter reaction, 4,5-cis-1-pyrrolines are selectively produced when the adducts are treated with LDA in the presence of lithium iodide.