An iridium-catalyzed cyclocondensation of amino alcohols and aldehydes is reported. Intramolecular allylic substitution by an enamine intermediate and subsequent in situ reduction furnishes 3,4-disubstituted piperidines with high enantiospecificity and good diastereoselectivity. The modular approach and the broad functional group tolerance provide access to diverse piperidine derivatives, which were further functionalized to give a versatile set of products.
Keywords: allylation; catalysis; iridium; piperidines; stereoselective synthesis.
© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.