title: Introducing copper as catalyst for oxidative alkane dehydrogenation.
abstract: The dehydrogenation of n-hexane and cycloalkanes giving n-hexene and cycloalkenes has been observed in the reaction of such hydrocarbons with hydrogen peroxide, in the presence of copper complexes bearing trispyrazolylborate ligands. This catalytic transformation provides the typical oxidation products (alcohol and ketones) with small amounts of the alkenes, a novel feature in this kind of oxidative processes. Experimental data exclude the participation of hydroxyl radicals derived from Fenton-like reaction mechanisms. DFT studies support a copper-oxo active species, which initiates the reaction by H abstraction. Spin crossover from the triplet to the singlet state, which is required to recover the catalyst, yields the major hydroxylation and minor dehydrogenation products. Further calculations suggested that the superoxo and hydroperoxo species are less reactive than the oxo. A complete mechanistic proposal in agreement with all experimental and computational data is proposed.
authors: Laboratorio de Catálisis Homogénea, Departamento de Química y Ciencia de los Materiales, Unidad Asociada al CSIC, Centro de Investigación en Química Sostenible, Universidad de Huelva, Campus de El Carmen, 21007 Huelva, Spain.
authors: Ana
authors: A
authors: Conde
authors: Laia
authors: L
authors: Vilella
authors: David
authors: D
authors: Balcells
authors: M Mar
authors: MM
authors: Díaz-Requejo
authors: Agustí
authors: A
authors: Lledós
authors: Pedro J
authors: PJ
authors: Pérez
mesh_terms: D000438:Alcohols / Q000138:chemical synthesis* / Q000737:chemistry; D000473:Alkanes / Q000737:chemistry*; D000475:Alkenes / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D006865:Hydrogenation; D007659:Ketones / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D010084:Oxidation-Reduction; D011789:Quantum Theory
chemical_list: D000438:Alcohols; D000473:Alkanes; D000475:Alkenes; D007659:Ketones; D003300:Copper