title: Catalyst-controlled regioselectivity in the synthesis of branched conjugated dienes via aerobic oxidative Heck reactions.
abstract: Pd-catalyzed aerobic oxidative coupling of vinylboronic acids and electronically unbiased alkyl olefins provides regioselective access to 1,3-disubstituted conjugated dienes. Catalyst-controlled regioselectivity is achieved by using 2,9-dimethylphenanthroline as a ligand. The observed regioselectivity is opposite to that observed from a traditional (nonoxidative) Heck reaction between a vinyl bromide and an alkene. DFT computational studies reveal that steric effects of the 2,9-dimethylphenanthroline ligand promote C-C bond formation at the internal position of the alkene.
authors.affiliation: Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, USA.
authors.forename: Changwu
authors.initials: C
authors.lastname: Zheng
authors.forename: Dian
authors.initials: D
authors.lastname: Wang
authors.forename: Shannon S
authors.initials: SS
authors.lastname: Stahl
mesh_terms: D000475:Alkenes / Q000737:chemistry; D001897:Boronic Acids / Q000737:chemistry; D002384:Catalysis; D010084:Oxidation-Reduction; D010165:Palladium / Q000737:chemistry; D011090:Polyenes / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000475:Alkenes; D001897:Boronic Acids; D011090:Polyenes; D010165:Palladium