Hydrogenation of ester, ketone or aldehyde groups with ruthenium complexes having di-amine and phosphorous-nitrogen bidentate ligand

Abstract

The present invention relates to the field of catalytic hydrogenation and, more particularly, to the use of specific ruthenium catalysts, or pre-catalysts, in hydrogenation processes with molecular H2 for the reduction of ketones, aldehydes and esters or lactones into the corresponding alcohol or diol respectively. Said catalysts are ruthenium complexes comprising a ligand of the type (N-N) type, in which at least one of said amino groups is a secondary or primary amine (i.e. a NH or NH2) and a ligand of the type (P-N) in which N belongs to a tertiary amino group, a N, N, N' trisubstituted carboxiamide (a C(=N)N moiety) or a N-substituted imidoate (a C(=N)O moiety).

Description

technical field [0001] The present invention relates to the field of catalytic hydrogenation, and more particularly to the application of specific ruthenium catalysts or precatalysts in the hydrogenation process for the reduction of ketones, aldehydes and esters or lactones to corresponding alcohols or diols, respectively. Background technique [0002] The reduction of ketone, aldehyde or ester functional groups to the corresponding alcohols is one of the fundamental reactions in organic chemistry and is used in a large number of chemical processes. In general, two main types of processes are known to effect this transformation, which are described below: [0003] a) Hydride process in which silyl or metal hydride salts such as LiAlH are used 4 Or use PMHS (polymethylhydrogensiloxane); [0004] b) Hydrogenation process in which molecular hydrogen is used. [0005] From a practical point of view, the hydrogenation process can be carried out by using very small amounts of c...

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Problems solved by technology

[0010] As long as the coordination spheres of the Ru complexes reported in the present technology are detached from the above P 2 N 2 type, then the structure of the reported complex is completely different, that is, there is only one bidentate ligand (see WO07 / 104690, Teller D.M et al., Tetrahedron Asymmetry, 2009, 550, or Miyake Y. et al., Synlett 2008, 1747, which discloses a coordination layer of the (PN)(P) type - and in the latter reference also requires the use of silane as a reduction aid), or in addition its very poor reactivity (see WO02 / 055195 publication N 4 type complex)

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