3-Carboxamide oxindoles as 1,3-C,N-bisnucleophiles for the highly diastereoselective synthesis of CF3-containing spiro-δ-lactam oxindoles featuring acyl at the ortho-position of spiro carbon atom

A simple and efficient strategy has been established for the synthesis of δ-lactam fused oxindoles via the Michael/N-hemiketalization cascade reaction of 3-carboxamide oxindoles and α,β-unsaturated trifluoromethyl ketones. A wide range of structurally novel CF3-containing spiro-δ-lactam oxindoles featuring acyl at the ortho-position of spiro carbon atoms were obtained in moderate to good yields with excellent diastereoselectivities under mild conditions. This work represents the first example of a systematic study of 3-carboxamide oxindoles as 1,3-C,N bisnucleophiles.