Affiliation:
1. Boreskov Institute of Catalysis Pr. Lavrentieva 5 630090 Novosibirsk Russia
2. Nikolaev Institute of Inorganic Chemistry Pr. Lavrentieva 3 630090 Novosibirsk Russia
3. Zelinsky Institute of Organic Chemistry RAS Leninsky Pr. 47 119991 Moscow Russia
Abstract
AbstractNickel(II) complexes with the simple N4 donor aminopyridine ligands BPMEN (N,N′‐dimethyl‐N,N′‐bis(2‐pyridylmethyl)‐1,2‐diaminoethane) and TPA (tris(2‐pyridylmethyl)amine) have been demonstrated to perform as efficient catalysts for the regioselective oxygenation of benzylic C−H groups with m‐chloroperoxybenzoic acid under mild conditions (at 20 °C), typically ensuring >90 % substrate conversions within 1 h at 1 mol % catalyst loadings. Unprecedentedly, replacing the commonly used mixed reaction solvent CH3CN/CH2Cl2 with 2,2,2‐trifluoroethanol diverts the selectivity of the above Ni‐based catalyst systems from hydroxylation/ketonization to trifluoroalkoxylation, with the formation of 1‐phenylalkyl 2,2,2‐trifluoroethyl ethers. The use of 2,2,2‐trifluoroethanol ensures high substrate conversion values (up to 97 %), as well as high selectivity for the ether formation (up to 92 %). Preliminary discussion of the reaction mechanism is given based on the catalytic and literature data.
Funder
Russian Science Foundation
Ministry of Science and Higher Education of the Russian Federation
Subject
Inorganic Chemistry,Organic Chemistry,Physical and Theoretical Chemistry,Catalysis