C-H Transformation in Industrial Processes

Scheme 1 summarizes the characteristics of the reactions, processes, and mechanistic aspects of this group of important chemical transformations, which form the basis of a large fraction of the current chemical industry. The reactions can be classified as intentional C-H transformations, carried out in aromatization reactions and in olefin synthesis, or as unintentional C-H transformations, for example isomerization reactions and all heteroatom functionalization such as oxidation or amination. 

The transition metal-catalyzed addition of the Si-H bond of a hydrosilane across a C=C or C=C bond is a transformation of considerable importance in both large-scale industrial processes and in small-scale organic synthesis.Perhaps the most common industrial application of catalytic hydrosilylation is the platinum-catalyzed cross-linking of vinylsilane polymers with hydrosilanes. The interest in catalytic hydrosilylation in organic synthesis... 

Up to now the so-called catalytic process is the only way to produce c-BN on an industrial scale. However, catalytic is not the correct scientific term, because the activation energy for transformation is not decreased by these substances. The substances which are used have the function of a solvent, and are responsible for the formation of c-BN. This method is successful because of the different solubilities of c-BN and h-BN in the flux. The precursor substances form a eutectic melt with the h-BN [152]. If the reaction conditions are in the domain of stable c-BN, spontaneous crystallization takes place and the c-BN growth rate is relatively high. 

Alkanes, which are the principal components of natural gas and crude oil, are still the preferred energy source of our society. In regard to the prime importance of alkanes as feedstock for the chemical industry, it appears a waste of resources simply to burn these precious raw materials. Unfortunately, attempts to transform alkanes into more valuable products are hampered by their low reactivity, as best illustrated by the use of alkanes as inert solvents. For example, the cracking process requires temperatures of about 1000 °C in order to convert long-chain alkanes into short-chain alkanes. Controlled conversion of hydrocarbons is difficult to achieve and limited to partial oxidations, such as the conversion of butane into acetic acid. It is obvious that processes that would enable efficient functionalization to occur at low temperature would have enormous potential application. Achievements towards this goal will almost certainly rely on the use of catalysts, which will have to activate the stable C-H bond (375-440 kf mol-1) in order to induce its scission. 

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