In-silico design of iridium catalysts for borylation and amidation of methane

Abstract

Research utilizing the activation of C–H bonds in hydrocarbons has been an important research topic for a long time. Although studies for the activation of various hydrocarbons have been carried out so far, only limited utilization of methane was possible. In this study, we aimed to understand the reaction mechanism of methane functionalization reaction catalysts by using computational chemistry and developing a catalyst that can be combined with various coupling partners by utilizing it. Inspired by previous studies of borylation reactions, studies on the borylation of methane gas have been conducted. The initial catalyst was designed based on an iridium catalyst which enabled various hydrocarbons to be activated, and the possibility of methane gas activation reaction with Ir(1,10-phenanthroline)(Bpin)3 was confirmed. The experiment was able to obtain monoborylated methane with a low yield consistent with our prediction. In order to solve these problems, a study was made on bidentate phosphorus ligands based on phosphorus, which is a softer base compared to nitrogen. Interestingly, in the case of Ir(dmpe)(Bpin)3, the transition state showing the highest barrier of calculated energy profile was lower than that of Ir(1,10-phenanthroline)(Bpin)3. Through the experimental confirmation, monoborylated methane yielded an initial result of 104 conversions with a yield of 52% and recently was able to increase conversions up to 170. In addition, an extensional study was made to convert the borylation catalysis into a nitrogen-containing coupling partner. In this process, we have been able to design a direct carbon-nitrogen bond catalyst using dioxazole derivatives. By utilizing a driving force that removes carbon dioxide or acetone from dioxazole derivatives, we were able to confirm the feasibility of using the proposed catalyst.