from first principles PP-I-1

OP-II-8Chiral Ionic Liquid/ESI-MS Methodology as an Efficient Tool for the Studyof Transformations of Supported OrganocatalystsZlotin S.G., Kuherenko A.S., Maltsev O.V., Chizhov A.O.N.D. Zelinsky Institute of Organic Chemistry RAS, Moscow, Russiazlotin@ioc.ac.ruAn efficient approach to the study of transformations of supported organocatalysts inasymmetric organocatalytic reactions by modifying them with ionic-liquid (IL) fragmentsfollowed by the ESI-MS analysis of recovered catalyst samples has been proposed. TheESI-MS(+) spectra of IL-modified catalysts contain mainly peaks of the catalyst and of ioniccompounds formed from the catalyst, whereas the molecules that do not contain ionic groupsgive much lower peaks. This approach was successfully applied to the study of deactivationpathways of O-TMS-prolinol [1] and primary amine-derived [2] chiral organocatalysts inasymmetric Michael reactions of nucleophiles (dialkylmalonates, nitroalkanes,hydroxycoumarin, or protected hydroxylamines) with -unsaturated carbonyl compoundsthat involved an iminium-ion formation step. The products of these reactions are used asintermediates for the synthesis of important chiral medications paroxetine, phenibut, baclofen,rolipram for curing CNS disorders, clinically useful anticoagulant warfarin and -aminoacideenantimers. This methodology allowed us to reveal undesirable side reactions that poisonedthe catalysts and found solutions (inert atmosphere or acidic reactivation) to increase theiroperation period. The proposed approach may be useful for the study of transformations ofother types of organocatalysts and for the development of new robust catalysts and processesthat would be suitable for large-scale industrial applications.The work was financially supported by the President of the Russian Federation (grant foryoung Ph.D. No. 3551.2012.3), the Russian Academy of Sciences (Basic Research ProgramNo. 1 of the Department of Chemistry and Material Sciences) and the Russian Foundation ofBasic Research (project 12-03-00420).References:[1] O.V. Maltsev, A.O. Chizhov, S.G. Zlotin. Chem. Eur. J., 2011, 17, 6109–6117.[2] A.S. Kucherenko, D.E. Siyutkin, A.G. Nigmatov, A.O. Chizhov, S.G. Zlotin. Adv. Synth. Catal.,2012, submitted.43