Novel and efficient aqueous phase synthesis of N-substituted azepines via tandem Michael addition and cyclization in the presence of β-cyclodextrin

N-substituted azepines were synthesized for the first time in water under neutral conditions by the reaction of aromatic amines, dimethyl/diethyl acetylene dicarboxylate, 2,5-dimethoxytetrahydrofuran mediated by β-cyclodextrin in high yields. β-Cyclodextrin can be recovered and reused with just a small loss of catalytic activity.