title: Regioselective synthesis of β-aryl- and β-amino-substituted aliphatic esters by rhodium-catalyzed tandem double-bond migration/conjugate addition.
abstract: Rhodium-phosphite catalysts were found to effectively mediate double-bond migrations within unsaturated esters. Once the double-bond is in conjugation with the carboxylate group, they also catalyze the Michael addition of carbon and nitrogen nucleophiles. In the presence of these catalysts, unsaturated carboxylates enter a dynamic equilibrium of positional and geometrical double-bond isomers. The conjugated species are continuously removed through 1,4-additions with formation of β-amino esters or β-arylated products, depending on the nucleophile employed. The applicability of both protocols to a range of substrates, such as fatty esters of different chain lengths and double-bond positions, and several nucleophiles including arylborates and primary and secondary amines, is demonstrated.
authors.affiliation: Fachbereich Chemie, Technische Universität Kaiserslautern, Erwin-Schrödinger-Strasse 54, 67663 Kaiserslautern, Germany.
authors.forename: Dominik M
authors.initials: DM
authors.lastname: Ohlmann
authors.forename: Lukas J
authors.initials: LJ
authors.lastname: Goossen
authors.forename: Markus
authors.initials: M
authors.lastname: Dierker