Solvent Directed Diastereodivergent Synthesis of Spiro‐Oxindoles with Quaternary Carbon Center Forming

An efficient method has been developed for the solvent‐directed diastereodivergent cyclization reactions with quaternary center formation. Various spiro‐oxindole diastereoisomers were synthesized with good yields (up to >99 %) and moderate to high diastereoselectivities (up to >20 : 1). Further study on NMR studies indicates that the key to this approach lies in different interactions between the substrate and organocatalyst across diverse solvents. This methodology may have significant implications for switchable, solvent‐directed diastereodivergent synthesis.