Abstract: This invention relates to a process for the reduction of .alpha.-,.beta.-unsaturated linear homo- and heterocyclic ketones by a transfer of hydrogen from an alcohol donor to said unsaturated ketone. The alcohol donor must be unsubstituted or substituted with an inert group. Also the alcohol donor may be a primary or secondary alcohol or a glycol. The process is a catalytic one and is carried out in the presence of complexed iridium and rhodium catalysts of the following formulae: ##STR1## wherein: M is selected from Ir and Rh;Chel represents a kelating bidentate nitrogenous compound;L--L represents a molecule of a preferably not conjugated diolefin, or two molecules of a mono-olefin;X.sup.- represents an anion selected from among: Cl.sup.-, Br.sup.-, J.sup.- ; PF.sub.6.sup.-, BF.sub.4.sup.-, CIO.sub.4.sup.-, B(C.sub.6 H.sub.5).sub.4.sup.

Abstract: Catalytic reduction of carbonyl compounds by transfer of hydrogen from alcohols to aliphatic, alicyclic, aromatic, homo- and heterocyclic ketones or aldehydes, catalyzed by rhodium or iridium complexes, characterized in that a primary or secondary alcohol of formula (I) or a glycol: ##STR1## is reacted with a ketonic compound of formula (II): ##STR2## in which R and R' and, respectively, R" and R'", optionally linked with each other according to homo- or heterocycles, indifferently represent a hydrogen atom or a hydrocarbyl group having up to 30 atoms of carbon, also substituted, provided that at least one of symbols R" and/or R'" is different respectively from R and/or R', in the presence of a complex catalyst of rhodium or of iridium selected from those having formulas (III) and (IV): ##STR3## wherein: M is selected from Rh and Ir;Chel is a chelating bidentate nitrogenous compound;L-L is a molecule of a preferably non-conjugated diolefin or two molecules of a monoolefin;X.sup.