Non-Covalent Carbonyl-Directed Heck-Matsuda Desymmetrizations: Synthesis of Cyclopentene-Fused Spirooxindoles, Spirolactones, and Spirolactams

Enantioselective carbonyl-directable Heck reactions using aryldiazonium salts were developed with the aim to construct chiral quaternary spiro centers in an efficient manner. Five-and six-membered spirooxindoles, spirolactones, and spirolactams (36 examples) were obtained in good to excellent isolated yields with diastereoselectivities ranging from 13:1 to >20:1, and enantiomeric excesses up to 99% in short reaction times (1.0-1.5 h) under mild conditions (40 degrees C). A rationale for the diastereo- and enantioselectivity based on an unprecedented non-covalent carbonyl group directing effect is also presented, and supported by computational calculations. (AU)