Understanding and exploiting C–H bond activation

Abstract

The selective transformation of ubiquitous but inert C H bonds to other functional groups has far-reaching practical implications, ranging from more efficient strategies for fine chemical synthesis to the replacement of current petrochemical feedstocks by less expensive and more readily available alkanes. The past twenty years have seen many examples of C-H bond activation at transition-metal centres, often under remarkably mild conditions and with high selectivity. Although profitable practical applications have not yet been developed, our understanding of how these organometallic reactions occur, and what their inherent advantages and limitations for practical alkane conversion are, has progressed considerably. In fact, the recent development of promising catalytic systems highlights the potential of organometallic chemistry for useful C-H bond activation strategies that will ultimately allow us to exploit Earth's alkane resources more efficiently and cleanly.

Direct conversion of methane under nonoxidative conditions

“…In fact, transition metal centers play crucial roles in the recent development of promising catalytic systems for C-H activation reactions in homogeneous catalysis, and considerable mechanistic insight has been gained. Labinger and Bercaw recently reviewed this topic in a publication [65]. Therefore, it may be appropriate to utilize to the increasing knowledge in the fields of transition metal chemistry and homogeneous catalysis gained at the molecular level when attempting to understand the nature and mechanism of the MDA reaction over the Mo/HZSM-5 catalysts.…”

Enzyme-mediated biodegradation of long-chain n-alkanes (C32 and C40) by thermophilic bacteria

“…While, there are special group of microorganisms that can biodegrade and biotransform these hydrocarbons and alkanes to assimilate as biomass in the ecosystem (Chikere et al 2012;Rajasekar et al 2012;Roy et al 2015;Kumar et al 2016). However, few alkanes are recalcitrant in the environment (e.g., long chain and high molecular weight hydrocarbons) due to their non-polar and chemically inert nature (Labinger and Bercaw 2002). Extensive research studies and reviews reported the biodegradation of the short chain hydrocarbons, while very limited studies reported the alkane and long-chain hydrocarbon degradations, especially under thermophilic conditions (Sakai et al 1994;Ko and Lebeault 1999;Hasanuzzaman et al 2007).…”

Activation of Carbon−Hydrogen and Hydrogen−Hydrogen Bonds by Copper−Nitrenes: A Comparison of Density Functional Theory with Single- and Multireference Correlation Consistent Composite Approaches

“…In this work, first-principles modeling of nitrene insertion into C-H and H-H bonds has been performed. Reactions of a -diketiminate-Cu-nitrene (i.e., L′Cu(NH); L′ is the parent -diketiminate anion, C 3 N 2 H 5 -) with H 2 and CH 4 have been performed in order to understand strong (BDE MesH ∼ 104 kcal mol -1 ) bond activation. Also, we seek to probe the impact of changes to the level of theory beyond approaches (i.e., B3LYP and Pople-style basis sets) now commonplace in the literature.…”