Diverse Annulations of Alkyl(phenyl)phosphinic Chlorides and Imines

The reactivity of alkyl(aryl)phosphinic chlorides and imines was investigated in the presence of a base. The results indicated that allyl/benzyl(aryl)phosphinic chlorides gave rise to 1,2-azaphosphines (δ-phostims), while nonbenzylic alkyl(aryl)phosphinic chlorides produced the corresponding β-phosphinolactams (β-phostims) in their reaction with cyclic dibenzo[b,f][1,4]oxazepines, whereas steric electron-rich arylmethyl(aryl)phosphinic chlorides generated [2 + 2 + 2] annuloadducts in some cases. The current investigation provides useful insight into the reactivity of phosphinic chlorides and imines.