Selective electrophilic activation of alkanes

• Published in: Accounts of chemical research Vol. 26; no. 7; pp. 370 - 376
• Main Authors: Sommer, Jean, Bukala, Jozef
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 01.07.1993
• Subjects: 400201 - Chemical & Physicochemical Properties; ALKANES; ANTIMONY COMPOUNDS; ANTIMONY FLUORIDES; CATALYSIS; CHEMICAL ACTIVATION; DEUTERIUM COMPOUNDS; FLUORIDES; FLUORINE COMPOUNDS; HALIDES; HALOGEN COMPOUNDS; HOMOGENEOUS CATALYSIS; HYDROCARBONS; HYDROGEN COMPOUNDS; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ORGANIC COMPOUNDS; REACTION INTERMEDIATES
• ISSN: 0001-4842; 1520-4898
• DOI: 10.1021/ar00031a003

One major drawback for the direct use of alkanes as chemicals is their chemical inertness toward most of the usual reagents. For this reason, costly, large-scale refinery operations such as catalytic reforming and vapocracking are needed, which necessitate the use of noble metal catalysts and/or high temperature to activate the strong C-H and C-C bonds and yield the primary chemical building blocks such as ethylene, propylene, butadiene, benzene, toluene, and xylene. In response to the challenge to use more economically a larger share of alkanes, and increasing number of research groups are working on the activation functionalization processes of the saturated hydrocarbon C-H bond. The goal is to overcome smoothly and selectively the chemical inertness of the starting (paraffinic) material. A book and special issue have been published recently on this subject. Protonated alkanes are reaction intermediates in superacid-catalyzed protolysis. Protonation occurs on all C-C and C-H [sigma]-bonds independently of the further reactivity of the protonated alkane as confirmed by using [sup 2]H labeled superacids. Direct and selective C-H bond protolysis is limited to tertiary alkanes whereas linear alkanes undergo less selective C-C bond cleavage. 31 refs., 3 figs.