Selective oxidation of C-H bonds is required for reactions ubiquitous in the chemical industry and understanding the mechanisms of these reactions will accelerate the development of the next generation of catalysts. Highly selective homogeneous cobalt catalysts bearing phosphine oxide ligands are synthesized to support mechanistic studies that investigate what drives selectivity in ethylbenzene oxidation, as a model reaction. Computational studies considered three mechanisms: (1) an external outer-sphere reaction wherein the metal’s primary role is facilitating radical formation, (2) inner-sphere coordination of the substrate combined with outer-sphere radical formation in a semi-external pathway, and (3) a fully inner-sphere reaction where oxidation is carried out by an attack from a Lewis base. Experimental and computational kinetic modeling together with byproduct analysis suggests that the reaction proceeds with the highest activity and selectivity for the methyl ketone product by the second pathway. By elucidating this reaction mechanism, we show how both inner-sphere and outer-sphere coordination must be controlled to achieve high selectivity in C-H oxidation catalysis.<br/>&lt;style type="text/css"&gt;.tb_button {padding:1px;cursor:pointer;border-right: 1px solid #8b8b8b;border-left: 1px solid #FFF;border-bottom: 1px solid #fff;}.tb_button.hover {borer:2px outset #def; background-color: #f8f8f8 !important;}.ws_toolbar {z-index:100000} .ws_toolbar .ws_tb_btn {cursor:pointer;border:1px solid #555;padding:3px}   .tb_highlight{background-color:yellow} .tb_hide {visibility:hidden} .ws_toolbar img {padding:2px;margin:0px}&lt;/style&gt;

Selective c-h oxidation of ethylbenzene to acetophenone using cobalt phosphine oxide complexes<br>

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.