Catalytic Acceptorless Dehydrogenation of Amines with Ru(P^R2N^R′2) and Ru(dppp) Complexes

Authors

James M. Stubbs, The University of Western Ontario
Richard J. Hazlehurst, The University of Western Ontario
Paul D. Boyle, The University of Western Ontario
Johanna M. Blacquiere, The University of Western OntarioFollow

Document Type

Article

Publication Date

5-8-2017

Journal

Organometallics

Volume

36

Issue

9

First Page

1692

Last Page

1698

URL with Digital Object Identifier

10.1021/acs.organomet.6b00870

Abstract

[Ru(Cp)(PPh2NBn2)(MeCN)]PF6 (1; PPh2NBn2 = 1,5-benzyl-3,7-phenyl-1,5-diaza-3,7-diphosphacyclooctane) and [Ru(Cp)(dppp)(MeCN)]PF6 (2; dppp = 1,3-bis(diphenylphosphino)propane) are both active toward the acceptorless dehydrogenation of benzylamine (BnNH2) and N-heterocycles. The two catalysts have similar activities but different selectivities for dehydrogenation products. Independent synthesis of a [Ru(Cp)(PPh2NBn2)(NH2Bn)]PF6 adduct (3) reveals the presence of a hydrogen bond between the bound amine and the pendent base of the PPh2NBn2 ligand. Preliminary mechanistic studies reveal that the benzylamine adduct is not an on-cycle catalyst intermediate.