title: A decarboxylative approach for regioselective hydroarylation of alkynes.
abstract: Regioselective activation of aromatic C-H bonds is a long-standing challenge for arene functionalization reactions such as the hydroarylation of alkynes. One possible solution is to employ a removable directing group that activates one of several aromatic C-H bonds. Here we report a new catalytic method for regioselective alkyne hydroarylation with benzoic acid derivatives during which the carboxylate functionality directs the alkyne to the ortho-C-H bond with elimination in situ to form a vinylarene product. The decarboxylation stage of this tandem sequence is envisioned to proceed with the assistance of an ortho-alkenyl moiety, which is formed by the initial alkyne coupling. This ruthenium-catalysed decarboxylative alkyne hydroarylation eliminates the common need for pre-existing ortho-substitution on benzoic acids for substrate activation, proceeds under redox-neutral and relatively mild conditions, and tolerates a broad range of synthetically useful aromatic functionality. Thus, it significantly increases the synthetic utility of benzoic acids as easily accessible aromatic building blocks.
authors.affiliation: Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58102, USA.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, University of California, Berkeley, California 94720, USA.
authors.forename: Ruja
authors.initials: R
authors.lastname: Shrestha
authors.affiliation: Department of Chemistry, University of California, Berkeley, California 94720, USA.
authors.forename: John F
authors.initials: JF
authors.lastname: Hartwig
authors.affiliation: Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58102, USA.
authors.forename: Pinjing
authors.initials: P
authors.lastname: Zhao