An Asymmetric Aryne‐capture Cascade Process : Tunable and Regiodivergent Synthesis of Chiral 2‐Aminobenzylamines by a Three‐Component Reaction

Wright, Noah and Halcovitch, Nathan R. and Mala, Bara and Ogunmola, Priscilla and Sweeney, Joseph B. and Doulcet, Julien (2026) An Asymmetric Aryne‐capture Cascade Process : Tunable and Regiodivergent Synthesis of Chiral 2‐Aminobenzylamines by a Three‐Component Reaction. Advanced Synthesis & Catalysis, 368 (7): e70329. ISSN 1615-4150

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Abstract

Despite the growing interest in arynes as versatile synthetic intermediates, their use in stereoselective reactions that deliver chiral products remains rare. Here, we describe the first example of a stereoselective cascade reaction of arynes with aryl amines and chiral sulfinimines, which efficiently furnishes 2‐aminobenzylamine products via a tandem aryne capture–electrophile quench–rearrangement cascade. The observed stereochemical outcomes indicate that the high levels of asymmetric induction, achieved during the electrophile quench with Ellman sulfinimines, arise from an open transition state, favored in strongly coordinating solvents. Mechanistic studies support the operation of two competing rearrangement processes in the final step, viz., intermolecular methyl migration and Smiles‐type rearrangement. Crucially, the reaction conditions can be tuned to access either 2‐aminobenzylamine regioisomers with highselectivity: high concentration favors the methyl‐migration product, while more dilution and/or the incorporation of electron withdrawing groups on the aryl amine steer the reaction toward the Smiles rearrangement pathway.