title: Triazole-Based Anion-Binding Catalysis for the Enantioselective Dearomatization of N-Heteroarenes with Phosphorus Nucleophiles.
abstract: The first enantioselective synthesis of chiral heterocyclic α-amino phosphonates by nucleophilic dearomatization of quinolines and pyridines using an anion-binding organocatalysis approach is described. Chiral tetrakistriazoles were employed as efficient hydrogen-bond donor catalysts by forming a chiral close ion-pair with the in situ formed N-acyl salts and 2,2,2-trichlorethoxycarbonyl chloride (TrocCl). The ion-pair was subsequently treated with various phosphorus nucleophiles, such as silyl-protected dialkyl- and trialkylphosphites. Thus, the corresponding products were obtained in complete or high regioselectivities and up to 97:3 e.r. for quinolines or up to 89:11 e.r. for the more challenging pyridine substrates. This method allows for rapid access to substituted chiral cyclic α-amino phosphonates, which can be easily transformed into phosphonic acid derivatives.
authors.affiliation: Institute for Organic Chemistry, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany.
authors.forename: Theresa
authors.initials: T
authors.lastname: Fischer
authors.affiliation: Institute for Organic Chemistry, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany.
authors.forename: Qui-Nhi
authors.initials: QN
authors.lastname: Duong
authors.affiliation: Institute for Organic Chemistry, University of Regensburg, Universitätsstr. 31, 93053, Regensburg, Germany.|Straubing Center of Science for Renewable Resources, 94315, Straubing, Germany.
authors.forename: Olga
authors.identifier: http://orcid.org/0000-0002-7578-5418
authors.initials: O
authors.lastname: García Mancheño
keywords: anion-binding; asymmetric catalysis; dearomatization; phosphorus nucleophiles; triazoles