Highly Diastereoselective Cascade [5+1] Double Michael Reaction, a Route for The Synthesis of Spiro Thio-Oxindoles
Journal: Research Square
Year: 2021

Abstract The first diastereoselective synthesis of spiro-thiooxindole is reported via Michael reaction between thiooxindoles and divinyl ketones. The reaction was conducted without any catalyst or additive under green conditions, i.e., ethanol as the solvent and room temperature. This study showed the art of governing regioselectivity in which novel spiro frameworks were generated in high yields. In addition to simple and column chromatography-free purification, the high diastereoselectivity mak