Silver-mediated radical 5-exo-dig cyclization of 2-alkynylbenzonitriles: synthesis of phosphinylated 1-indenones

Abstract

A new silver-mediated 5-exo-dig cyclization of 2-alkynylbenzonitriles with disubstituted phosphine oxide and H₂O has been developed. The reaction enables multiple bond-forming events including C-P, C-C and C-O bonds under atmospheric conditions, leading to the concise and direct formation of 28 examples of phosphorus-containing 1-indenones with generally good yields.