Bismuth‐Mediated α‐Arylation of Acidic Diketones with <i>ortho</i> ‐Substituted Boronic Acids

The α-arylation of cyclic and fluoroalkyl 1,3-diketones is made challenging by the highly stabilized nature corresponding enolates, especially difficult for sterically demanding aryl partners. As a general solution to this problem, we report Bi-mediated oxidative coupling acidic diones ortho-substituted arylboronic acids. Starting from bench-stable bismacycle precursor, sequence B-to-Bi transmetallation, oxidation C−C bond formation furnishes arylated diones. Development methodology that tolerates both sensitive functionality steric demand supported interrogation key reactive intermediates. Application our strategy enables concise synthesis important agrochemical intermediates which were previously prepared using toxic Pb reagents. This also first ever arylation which, upon condensation with hydrazine, provides direct access valuable pyrazoles.