title: Enantioselective Visible-Light-Induced Radical-Addition Reactions to 3-Alkylidene Indolin-2-ones.
abstract: The title compounds underwent a facile and high-yielding addition reaction (19 examples, 66-99% yield) with various N-(trimethylsilyl)methyl-substituted amines upon irradiation with visible light and catalysis by a metal complex. If the alkylidene substituent is non-symmetric and if the reaction is performed in the presence of a chiral hydrogen-bonding template, products are obtained with significant enantioselectivity (58-72% ee) as a mixture of diastereoisomers. Mechanistic studies suggest a closed catalytic cycle for the photoactive metal complex. However, the silyl transfer from the amine occurs not only to the product, but also to the substrate, and interferes with the desired chirality transfer.
authors.affiliation: Department Chemie and Catalysis Research Center (CRC), Technische Universität München, Lichtenbergstrasse 4, 85747, Garching, Germany), Fax.
authors.forename: Dominik
authors.initials: D
authors.lastname: Lenhart
authors.affiliation: Department Chemie and Catalysis Research Center (CRC), Technische Universität München, Lichtenbergstrasse 4, 85747, Garching, Germany), Fax.
authors.forename: Andreas
authors.initials: A
authors.lastname: Bauer
authors.affiliation: Department Chemie and Catalysis Research Center (CRC), Technische Universität München, Lichtenbergstrasse 4, 85747, Garching, Germany), Fax.
authors.forename: Alexander
authors.initials: A
authors.lastname: Pöthig
authors.affiliation: Department Chemie and Catalysis Research Center (CRC), Technische Universität München, Lichtenbergstrasse 4, 85747, Garching, Germany), Fax. thorsten.bach@ch.tum.de.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Bach
keywords: enantioselectivity; hydrogen bonds; photochemistry; radical reactions; ruthenium