Mechanistic Studies on the Bidentate Lewis Acid Catalyzed Domino Inverse Electron‐Demand Diels‐Alder/Thiol Transfer Reaction

Abstract Recently, we presented a novel enantioselective multicomponent reaction of phthalazines, aldehydes and thiols accessing thioether‐substituted 1,2‐dihydronaphthalenes. Herein, comprehensive investigation on the mechanism this domino inverse electron‐demand (IEDDA)/thiol transfer is disclosed. In particular, origin stereochemical outcome has been rationalized, as well structural requirement thiol component for an efficient step. Detailed NMR spectroscopy studies uncover competing pathway resulting in N , S ‐acetals. addition, DFT computations illuminate group process enable explanation formation most dominant by‐product. The insights allow direct prediction suitable substrates provide basis further developments stereoselective reactions.