Enantioselective Transfer Hydrogenation of Ketones Catalyzed by a Manganese Complex Containing an Unsymmetrical Chiral PNP′ Tridentate Ligand. Issue 10 (31st March 2017)

• Record Type: Journal Article
• Authors: Zirakzadeh, Afrooz; de Aguiar, Sara R. M. M.; Stöger, Berthold; Widhalm, Michael; Kirchner, Karl
• Is Part Of: ChemCatChem. Volume 9:Issue 10(2017)
• Page Start: 1744
• Page End: 1748
• Publication Date: 2017-03-31
• Subjects: asymmetric synthesis -- chiral ligands -- hydride ligands -- hydrogenation -- manganese; Catalysis -- Periodicals; 541.39505
• DOI: 10.1002/cctc.201700042
• Languages: English
• ISSNs: 1867-3880

Abstract

Abstract: Manganese complexes of the types [Mn(PNP′)(Br)(CO)2 ] and [Mn(PNP′)(H)(CO)2 ] containing a tridentate ligand with a planar chiral ferrocene and a centro chiral aliphatic unit were synthesized, characterized, and tested in the enantioselective transfer hydrogenations of 13 ketones. The catalytic reactions proceeded with conversions up to 96 % and ee values up to 86 %. The absolute configuration of all products was determined to be ( S ). Notably, the presence of dihydrogen (up to 20 bar) did not affect the reduction. On the basis of DFT calculations, preliminary mechanistic details including the origin of the ( S ) selectivity are presented. The molecular structure of [Mn(PNP′)(Br)(CO)2 ] was studied by X‐ray diffraction. Abstract : Going into hyd‐ing : The first enantioselective transfer hydrogenation of ketones catalyzed by a well‐defined Mn‐based complex containing a chiral PNP′ pincer ligand with a planar chiral ferrocene and a centro chiral aliphatic unit is reported. The asymmetric transfer hydrogenation reactions procced under mild conditions with conversions up to 96 % and ee values up to 86 %.