title: Breaking the regioselectivity rule for acrylate insertion in the Mizoroki-Heck reaction.
abstract: In modern methods for the preparation of small molecules and polymers, the insertion of substrate carbon-carbon double bonds into metal-carbon bonds is a fundamental step of paramount importance. This issue is illustrated by Mizoroki-Heck coupling as the most prominent example in organic synthesis and also by catalytic insertion polymerization. For unsymmetric substrates H(2)C = CHX the regioselectivity of insertion is decisive for the nature of the product formed. Electron-deficient olefins insert selectively in a 2,1-fashion for electronic reasons. A means for controlling this regioselectivity is lacking to date. In a combined experimental and theoretical study, we now report that, by destabilizing the transition state of 2,1-insertion via steric interactions, the regioselectivity of methyl acrylate insertion into palladium-methyl and phenyl bonds can be inverted entirely to yield the opposite "regioirregular" products in stoichiometric reactions. Insights from these experiments will aid the rational design of complexes which enable a catalytic and regioirregular Mizoroki-Heck reaction of electron-deficient olefins.
authors.affiliation: Department of Chemistry, University of Konstanz, 78464 Konstanz, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Wucher
authors.forename: Lucia
authors.initials: L
authors.lastname: Caporaso
authors.forename: Philipp
authors.initials: P
authors.lastname: Roesle
authors.forename: Francesco
authors.initials: F
authors.lastname: Ragone
authors.forename: Luigi
authors.initials: L
authors.lastname: Cavallo
authors.forename: Stefan
authors.initials: S
authors.lastname: Mecking
authors.forename: Inigo
authors.initials: I
authors.lastname: Göttker-Schnetmann
mesh_terms: D000475:Alkenes / Q000737:chemistry; D002244:Carbon / Q000737:chemistry; D002384:Catalysis; D002621:Chemistry / Q000379:methods*; D004581:Electronics; D004583:Electrons; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008670:Metals / Q000737:chemistry; D008956:Models, Chemical; D008968:Molecular Conformation; D015394:Molecular Structure; D010165:Palladium / Q000737:chemistry*; D012984:Software; D013237:Stereoisomerism; D013696:Temperature
chemical_list: D000475:Alkenes; D008670:Metals; D010165:Palladium; D002244:Carbon