Mechanistic Insights of a Selective C-H Alkylation of Alkenes by a Ru-based Catalyst and Alcohols

Abstract

Density functional theory calculations have been used to investigate the reaction mechanism for [(C6H6)(PCy3)(CO) RuH](+) (1; Cy, cyclohexyl) mediated alkylation of indene substrate using ethanol as solvent. According to Yi et al. [ Science 2011, 333, 1613] the plausible reaction mechanism involves a cationic Rualkenyl species, which is initially formed from 1 with two equivalents of the olefin substrate via the vinylic C-H activation and an alkane elimination step. Once the active catalytic species is achieved the oxidative addition step is faced. The latter step together with the next C-C bond formation might display the upper barrier of the catalytic cycle. Having these experimental insights at hand, we investigated in detail the whole reaction pathway using several computational DFT approaches including alternative pathways, higher in energy

Alcohols as Substrates in Transition-Metal-Catalyzed Arylation, Alkylation, and Related Reactions

“…The authors proposed that a vinyl ruthenium intermediate may form that activates the alcohol by oxidative addition/reductive elimination. The mechanism was studied in depth by Cavallo, Poater, and coworkers, 263,264 who corroborated this hypothesis. The Yi group followed up this work with a series of papers over the following decade, demonstrating the functionalization of phenols with aliphatic alcohols (Scheme 43b), 265 the etherification of two alcohols, 266 and the reductive etherification of alcohols with aldehydes or ketones in the presence of H 2 .…”

Recent DFT Calculations on the Mechanism of Transition‐Metal‐Catalyzed C−O Activation of Alcohols

“…The early C−O bond activation of alcohols have proposed some remarkable breakthroughs as well as appealing reaction mechanisms [48–53] . Although limited by the experimental strategies or computational availability, these DFT findings have inspired the further exploitation of comprehensive and generalized activation solutions.…”

“…The early CÀ O bond activation of alcohols have proposed some remarkable breakthroughs as well as appealing reaction mechanisms. [48][49][50][51][52][53] Although limited by the experimental strategies or computational availability, these DFT findings have inspired the further exploitation of comprehensive and generalized activation solutions. This review presents selected mechanistic studies on these aspects of theoretical calculations in recent years, an in-depth discussion of the mechanisms and selectivity of the reactions, and a summary and outlook of the development prospects and potential challenges in this field.…”