abstracts - Институт катализа им. Г.К. Борескова

OP-II-25ASYMMETRIC HYDROGENATION OF KETONES CATALYSED BY CHIRALPLANAR PHOSPHINE THIOETHER IRIDIUM COMPLEXESMalacea R., E. Le Roux 1 , Manoury E., Poli R., Gonsalvi L. 1 , Peruzzini M. 1Laboratoire de Chimie de Coordination, UPR-CNRS 8241 liée par convention à l’Universitépaul Sabatier et à l’Institut National Polytechnique de Toulouse , 205 Route de Narbonne,F-31077 Toulouse Cedex, France1 Istituto di Chimica dei Composti Organo Metallici, Via Madonna del Piano 10, PoloScientifico di Sesto Fiorentino, I-50019 Sesto Fiorentino, Italy.E-mail: poli@lcc-toulouse.frThe catalytic hydrogenation of polar bonds and the asymmetric versions of these are keyreactions in fine chemical and pharmaceutical synthesis. In 2001 Noyori described newBINAP/diamine ruthenium complexes which are productive and highly enantioselectivecatalysts for the hydrogenation of a range of aromatic, heteroaromatic and unsaturated ketonesin 2-propanol containing tBuOK or KOH. 1 For example, acetophenone and its derivatives arehydrogenated with substrate:catalyst ratios up to 100.000:1, to give the secondary alcoholsquantitatively with 99% e.e.The hydrogenation of the same type of substrates with other metals has received lessattention. Dahlenberg and Gotz developped β-Aminophosphane iridium complexes which actas catalysts for the direct hydrogenation alkyl aryl ketones to the corresponding 1-phenylalkanols, if combined with an alkaline or amine base in methanol under H 2 (50 bar)between 25 and 50°C. 2 The reaction occurs with TOF from 1 to 30 h -1 and moderateenantioselectivities (20-75% e.e.). Water soluble diamine iridium catalysts have been testedin asymmetric hydrogenation of ketones and also give moderate enantioselectivities(40-50 %) for TOF from 1 to 50 h -1 . 3We have recently reported new planar-chiral P,S ferrocenyl ligands 4 and have exploredtheir iridium coordination chemistry (scheme 1). 5 These complexes proved to have a verygood activity for the hydrogenation of various alkyl aryl ketones (TOF 150 to 250 h -1 ) and agood enantioselectivity (77% e.e. for R = benzyl). The simultaneous presence of H 2 (30 bar)and an alcohol solvent (except for tBuOH) and a base (KOH, MeONa) were found to benecessary for the hydrogenation. Other mechanistic details will also be presented anddiscussed.247