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Development and mechanistic investigation of the manganese(iii) salen-catalyzed dehydrogenation of alcohols.

ABSTRACT: The first example of a manganese(iii) catalyst for the acceptorless dehydrogenation of alcohols is presented. N,N'-Bis(salicylidene)-1,2-cyclohexanediaminomanganese(iii) chloride (2) has been shown to catalyze the direct synthesis of imines from a variety of alcohols and amines with the liberation of hydrogen gas. The mechanism has been investigated experimentally with labelled substrates and theoretically with DFT calculations. The results indicate a metal-ligand bifunctional pathway in which both imine groups in the salen ligand are first reduced to form a manganese(iii) amido complex as the catalytically active species. Dehydrogenation of the alcohol then takes place by a stepwise outer-sphere hydrogen transfer generating a manganese(iii) salan hydride from which hydrogen gas is released.

SUBMITTER: Samuelsen SV

PROVIDER: S-EPMC6349018 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature

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Development and mechanistic investigation of the manganese(iii) salen-catalyzed dehydrogenation of alcohols.

Samuelsen Simone V SV Santilli Carola C Ahlquist Mårten S G MSG Madsen Robert R

Chemical science 20181113 4

The first example of a manganese(iii) catalyst for the acceptorless dehydrogenation of alcohols is presented. N,N'-Bis(salicylidene)-1,2-cyclohexanediaminomanganese(iii) chloride (2) has been shown to catalyze the direct synthesis of imines from a variety of alcohols and amines with the liberation of hydrogen gas. The mechanism has been investigated experimentally with labelled substrates and theoretically with DFT calculations. The results indicate a metal-ligand bifunction ...[more]

PMID: 30774913

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