Enantioselective Hydrogenation of Imidazo[1,2-a]pyridines
Christoph Schlepphorst1, Mario P Wiesenfeldt1, Frank Glorius1
1Westfälische Wilhelms-Universität Münster, Organisch-Chemisches Institut, Corrensstrasse 40, 48149, Münster, Germany.
Abstract:
The enantioselective synthesis of tetrahydroimidazo[1,2-a]pyridines by direct hydrogenation was achieved using a ruthenium/N-heterocyclic carbene (NHC) catalyst. The reaction forgoes the need for protecting or activating groups, proceeds with complete regioselectivity, good to excellent yields, enantiomeric ratios of up to 98:2, and tolerates a broad range of functional groups. 5,6,7,8-Tetrahydroimidazo[1,2-a]pyridines, which are found in numerous bioactive molecules, were directly obtained by this method, and its applicability was demonstrated by the (formal) synthesis of several functional molecules.
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