Synlett 2014; 25(19): 2681-2685
DOI: 10.1055/s-0034-1379246
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© Georg Thieme Verlag Stuttgart · New York

Condensation Versus Hydroamination for the Direct, Catalytic Synthesis of Tetrasubstituted Propargylamines

Keegan G. Nelson
Department of Chemistry, University of California, Riverside, 501 W. Big Springs Road, Riverside, CA 92521, USA   Fax: +1(951)827-4713   Email: catharine.larsen@ucr.edu
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Catharine H. Larsen*
Department of Chemistry, University of California, Riverside, 501 W. Big Springs Road, Riverside, CA 92521, USA   Fax: +1(951)827-4713   Email: catharine.larsen@ucr.edu
› Author Affiliations
Further Information

Publication History

Received: 02 August 2014

Accepted: 10 September 2014

Publication Date:
17 October 2014 (online)


Abstract

Multicomponent couplings of carbonyls, amines, and nucleophiles provide a wide array of trisubstituted carbons bearing amines but tetrasubstituted products are rarely formed. Cooperative copper/titanium catalysis under solvent-free conditions is required to overcome the barrier to condensation of a ketone with an amine and subsequent alkynylation. An alternative mode of accessing ket­imines is the Markovnikov hydroamination of alkynes. Heating a simple copper salt with an amine and a terminal alkyne rapidly produces tetrasubstituted propargylic amines via tandem hydroamination–alkynylation.