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Carboxylation of Arene CH Bonds with CO 2 : A DFT‐Based Approach to Catalyst Design
Author(s) -
Uhe Andreas,
Hölscher Markus,
Leitner Walter
Publication year - 2012
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201102785
Subject(s) - pincer movement , catalysis , carboxylation , catalytic cycle , ruthenium , chemistry , substrate (aquarium) , density functional theory , kinetics , photochemistry , solvent , combinatorial chemistry , computational chemistry , organic chemistry , oceanography , physics , quantum mechanics , geology
A prototypical catalytic cycle for the direct carboxylation of unactivated arene CH bonds with CO 2 based on ruthenium(II) pincer complexes as catalysts is proposed and investigated by density functional theory (DFT) methods. The energetic span model is used to predict the turnover frequency (TOF) of various potential catalysts, evaluating their efficiency for this reaction. In addition to modifications of the catalyst structure, we also investigated the effect of the substrate, the solvent, and the influence of a base on the thermodynamics and kinetics of the reaction. Turnover frequencies in the range of 10 5 –10 7 h −1 are predicted for the best systems. Alternative reaction pathways that might prevent the reaction are also investigated. In all cases, either the respective intermediates are found to be unstable or activation barriers are found to be very high, thereby indicating that these alternative pathways will not interfere with the proposed catalytic cycle. As a result, several ruthenium pincer complexes are suggested as very promising candidates for experimental investigation as catalysts for the carboxylation of arene CH bonds with CO 2 .