Precise Synthesis of Diastereomers of Spiro-oxindole Derivatives through Dynamic Covalent Transformation

In this study, [1+2+2] cyclization of tryptamine-derived isocyanides with 3-ylideneoxindoles was systematically investigated. A series of structurally complex spiro-oxindole derivatives were obtained. Characteristic dynamic covalent chemistry was observed and confirmed by experiments and density functional theory calculation. Through the regulation of the solvent, temperature, and time, the precise and stereodivergent synthesis of spiro-oxindoles was achieved.