Enantio- and <i>Z</i> / <i>E</i> -Stereodivergent Ni/Pd Dual Catalysisfor Trisubstituted AlkenesFeaturing α-Chiral Carbonyls

Abstract The stereoselective synthesis of highly substituted alkenes has long been a formidable challenge. While significant efforts have been directed toward controlling Z/E-selectivity, existing methods are largely incapable of achieving enantio- and Z/E-stereodivergent synthesis, in which all four stereoisomers [(Z,R); (Z,S); (E,R); (E,S)] were selectively obtained, respectively. Herein, we report a Ni/Pd synergistic catalysis for enantio- and Z/E-stereodivergent synthesis of trisubstituted alkenes featuring α-chiral carbonyls. A Z/E-mixture of readily available allylic carbonates were converted into either Z- or E-products in excellent yields with high enantio- and Z/E-selectivities via a Z/E-convergent asymmetric allylic substitution using 2-acylimidazole as nucleophile. DFT calculations revealed that a catalytic cavity, cooperatively formed by the Ni and Pd catalysts, precisely discerns the relative orientation (syn or anti) of the substituents on the π-allyl-Pd species within the competing transition states leading to Z- or E-products, thereby accounting for the high Z/E-selectivity. This method establishes a general platform for the enantio- and Z/E-stereodivergent synthesis of α-chiral ketones, carboxylic acids, amides, and esters featuring Z- or E-trisubstituted C═C bonds.