Synthesis of 1-Phospho-3-benzoxepins via a Silver-catalyzed Reaction of 2-Alkynylacetophenones with Diazomethylphosphonates.

A synthetic protocol for construction of 3-benzoxepin skeleton through a silver-catalyzed annulation/nucleophilic/ring-expansion reaction of 2-alkynylacetophenones with diazomethylphosphonates is described. This protocol provided a series of 1-phosphonate-3-benzoxepin analogs in yields of 39%-95%. The resulting benzoxepins featuring halogen and phosphonate could be further transformed into other derivatives. [ABSTRACT FROM AUTHOR]