Functionalization of N-Heterocycles in Transition Metal Catalyzed Reactions

Title : Functionalization of N-Heterocycles in Transition Metal Catalyzed Reactions

Abstract:

There are several ways of introducing acyl functionality into simple model compounds or skeletons of practical importance. The application of conventional acylating agents is well known and is referenced in reviews, handbooks and even textbooks. Since the discovery of the aminocarbonylation by Heck et al (‘Heck-carbonylation’),¹ the use of a primary or secondary amine, carbon monoxide and aryl/alkenyl halides (or their synthetic surrogates, aryl triflates and alkenyl triflates) in the presence of palladium catalysts lead to carboxamides in great variety.² 

Our presentation will be focused on the following topics:

1. The efficiency of palladium(II)-acyl intermediates, formed via carbon monoxide insertion into Pd-aryl/alkenyl bonds, as acylating agents will be exemplified.
2. The reaction mechanism will be rationalised on the basis of a catalytic cycle.
3. High-yielding palladium-catalysed aminocarbonylation of functionalised iodoaromatics and iodoalkenes towards carboxamides (via single CO insertion) and 2-ketocarboxamides (via double CO insertion) will be discussed. The functional group tolerance of the palladium-catalysed reaction will be shown.
4. The synthesis of compounds of pharmacological importance (penicillins, cephalosporins, etc.) will be discussed by choosing more complicated skeletons as N-nucleophiles in aminocarbonylation.
5. The efficiency of the combination of high-yielding conventional reactions and highly selective homogeneous catalytic reactions will be shown in multistep syntheses under green conditions.

Biography:

Laszlo Kollar received his diploma in 1979 and the doctoral degree in 1983 at the University of Veszprem, Hungary. He is now the Head of the Institute of Chemistry at the University of Pecs, Hungary. The main efforts of his current research are focused on the synthetic application of transition metal complexes regarding the functionalization of steroids and N-heterocycles of pharmacological importance, as well as PARP inhibitors. He is the author of more than 300 papers published in international journals and co-author of 9 basic patents on 5alfa-reductase inhibitors and agrochemicals.