Ring Opening of Organosilicon-Substituted Benzoxazolinone: A Convenient Route to Chelating Ureato and Carbamido Ligands

N-Silylated benzoxazolin-2-one reacts with N−H and C−H acidic heterocycles (benzoxazolinone, 3,5-dimethylpyrazole, N-methylimidazole) under benzoxazolinone ring cleavage and formation of ortho-siloxyphenyl-substituted ureas and carbamides, respectively. These products were shown to serve as sources for tridentate (O′NO) and (N′NO) chelating ligands.