title: New iridium catalysts for the selective alkylation of amines by alcohols under mild conditions and for the synthesis of quinolines by acceptor-less dehydrogenative condensation.
abstract: A novel family of iridium catalysts stabilised by P,N-ligands have been introduced. The ligands are based on imidazo[1,5-b]pyridazin-7-amines and can be synthesised with a broad variety of substitution patterns. The catalysts were synthesised quantitatively from the protonated ligands and a commercially available iridium precursor. The catalysts mediate the alkylation of amines by alcohols under mild conditions (70 °C). In addition, the synthesis of quinolines from secondary or primary alcohols and amino alcohols is reported. This sustainable synthesis proceeds through the liberation of two equivalents of water and two equivalents of dihydrogen. The investigations indicate that catalysts suitable for hydrogen autotransfer or borrowing hydrogen chemistry might also be suitable for acceptor-less dehydrogenative condensation reactions.
authors.affiliation: Lehrstuhl Anorganische Chemie II (Catalyst Design), Universität Bayreuth, Universitätsstrasse 30, NW I, 95440 Bayreuth (Germany), Fax: (+49) 921552157.
authors.forename: Susanne
authors.initials: S
authors.lastname: Ruch
authors.forename: Torsten
authors.initials: T
authors.lastname: Irrgang
authors.forename: Rhett
authors.initials: R
authors.lastname: Kempe
keywords: N,P ligands; alkylation; dehydrogenation; hydrogen; iridium