title: Palladium-catalyzed, direct boronic acid synthesis from aryl chlorides: a simplified route to diverse boronate ester derivatives.
abstract: Although much current research focuses on developing new boron reagents and identifying robust catalytic systems for the cross-coupling of these reagents, the fundamental preparations of the nucleophilic partners (i.e., boronic acids and derivatives) has been studied to a lesser extent. Most current methods to access boronic acids are indirect and require harsh conditions or expensive reagents. A simple and efficient palladium-catalyzed, direct synthesis of arylboronic acids from the corresponding aryl chlorides using an underutilized reagent, tetrahydroxydiboron B(2)(OH)(4), is reported. To ensure preservation of the carbon-boron bond, the boronic acids were efficiently converted to the trifluoroborate derivatives in good to excellent yields without the use of a workup or isolation. Further, the intermediate boronic acids can be easily converted to a wide range of useful boronates. Finally, a two-step, one-pot method was developed to couple two aryl chlorides efficiently in a Suzuki-Miyaura-type reaction.
authors.affiliation: Roy and Diana Vagelos Laboratories and Penn/Merck Laboratory for High Throughput Experimentation, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States. gmolandr@sas.upenn.edu
authors.forename: Gary A
authors.initials: GA
authors.lastname: Molander
authors.forename: Sarah L J
authors.initials: SL
authors.lastname: Trice
authors.forename: Spencer D
authors.initials: SD
authors.lastname: Dreher
mesh_terms: D001897:Boronic Acids / Q000138:chemical synthesis* / Q000737:chemistry*; D002384:Catalysis; D004952:Esters / Q000138:chemical synthesis* / Q000737:chemistry*; D006843:Hydrocarbons, Chlorinated / Q000737:chemistry*; D015394:Molecular Structure; D010165:Palladium / Q000737:chemistry*
chemical_list: D001897:Boronic Acids; D004952:Esters; D006843:Hydrocarbons, Chlorinated; D010165:Palladium