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Concerted Switching of Regio- and Stereochemistry in Reductive Hydroarylation of Phenylpropiolic Acid Derivatives:
Hui Li1, Xu Tian1, Qin-Qin Dang1
1School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, China.
Abstract:
Nickel-catalyzed reductive hydroarylation of phenylpropiolic esters with aryl halides overrides conventional electronic and stereochemical preferences delivering anti-α-hydroarylation products with high selectivity. The method tolerates aryl iodides and bromides, with chemoselective discrimination of iodides vs bromides by tuning reaction conditions. Mechanistic studies reveal a synergistic control mode: steric repulsion governs regioselectivity, while ester carbonyl coordination enables postinsertion Z/E isomerization. A Ni(0)/Ni(II)/Ni(I) manifold and protic solvent as hydrogen donor are supported by deuterium labeling and HRMS-ESI.
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