Affiliation:
1. Departamento de Química Universidad Simón Bolívar Valle de Sartenejas Baruta Apartado 89000 Caracas 1020-A Venezuela
2. Current address: Department of Chemistry and Biochemistry University of California, Merced 5200 Lake Rd Merced CA 95343 USA
3. Institute of Inorganic Chemistry University of Regensburg 93040 Regensburg Germany
4. Current address:Istituto di Chimica dei Composti Organometallici Consiglio Nazionale delle Ricerche Via Madonna del Piano 10 50019 Sesto Fiorentino Italy
5. Laboratorio de Química Bioinorgánica Centro de Química Instituto Venezolano de Investigaciones Científicas (IVIC) Carretera Panamericana Km. 11 Altos de Pipe Caracas 1020-A Venezuela
Abstract
AbstractA Rh(I) complex [κ2(P,N)‐{P(Oquin)3}RhCl(PPh3)] (1) bearing the P,N ligand tris(8‐quinolinyl)phosphite, P(Oquin)3, has been synthesized and structurally characterized. The molecular structure of complex 1 shows that P(Oquin)3 acts as a bidentate P,N chelate ligand. Reactivity studies of 1 reveal that the triphenylphosphine ligand can be replaced by Pcy3 or removed upon oxidation with concomitant coordination of a second 8‐quinolyl unit of P(Oquin)3. In addition, the Rh(III) complex [RhCl2{OP(Oquin)2}] (3), resulting from treating 1 with either wet CDCl3 or, sequentially, with HCl and water, was identified by X‐ray diffraction analysis. Complex 1 catalyzes the 1,2‐regioselective hydroboration of pyridines and quinolines, affording N‐boryl‐1,2‐dihydropyridines (1,2‐BDHP) and N‐boryl‐1,2‐hydroquinolines (1,2‐BDHQ) in high yield (up to >95 %) with turnover numbers (TONs) of up to 130. The system tolerates a variety of substrates of different electronic and steric nature. In comparison with other transition‐metal‐based hydroboration catalysts, this system is efficient at a low catalyst loading without the requirement of base or other additives.
Funder
Alexander von Humboldt-Stiftung
Universität Regensburg
German Academic Exchange Service