A Facile Approach for the Asymmetric Synthesis of Oxindoles with a 3‑Sulfenyl-Substituted Quaternary Stereocenter

With the employment of a threonine-incorporating multifunctional catalyst 9, Michael addition of 3-sulfenyloxindoles to nitroolefins proceeded stereoselectively, leading to the formation of oxindoles with a 3-sulfenyl-substituted quaternary center in excellent yields, and with high diastereoselectivities and excellent enantioselectivities.