title: Pd-Catalyzed Hydroborylation of Alkynes: A Ligand Controlled Regioselectivity Switch for the Synthesis of α- or β-Vinylboronates.
abstract: A ligand controlled selective hydroborylation of alkynes to α- or β-vinylboronates has been developed using a Pd catalyst. The high α-selectivity displayed by this reaction can be switched to furnish β-vinylboronates by altering the ligand from a trialkylphosphine to N-heterocyclic carbene. A variety of terminal alkynes are shown to furnish the corresponding α- or β-vinylboronates in good to excellent selectivity and yield. The mechanistic studies suggest that the solvent is the proton source and bromobenzene functions as an important additive in driving this reaction forward.
authors.affiliation: Department of Organic Chemistry, Indian Institute of Science , Bangalore 560012, Karnataka, India.
authors.forename: Devi Prasan
authors.initials: DP
authors.lastname: Ojha
authors.affiliation: Department of Organic Chemistry, Indian Institute of Science , Bangalore 560012, Karnataka, India.
authors.forename: Kandikere Ramaiah
authors.initials: KR
authors.lastname: Prabhu