Highly enantioselective copper-catalyzed propargylic amination to access N-tethered 1,6-enynes

Cu/Ag-Mediated One-Pot Enantioselective Synthesis of Fully Decorated 1,2,3-Triazolo[1,5-a]pyrazines

The synthesis of chiral triazole-fused pyrazine scaffolds from readily available substrates in a step-economical asymmetric catalytic way is highly appealing. We herein report that an efficient Cu/Ag relay catalyzed protocol employing cascade asymmetric propargylic amination, hydroazidation, and [3 + 2] cycloaddition reaction with high efficiency to access the target enantioenriched 1,2,3-triazolo[1,5-a]pyrazine has been accomplished by applying a novel N,N,P-ligand. The one-pot reaction of three components exhibits high functional group tolerance, excellent enantioselectivities, and a broad substrate scope with readily available starting materials.

Catalytic Asymmetric Vinylogous and Bisvinylogous Propargylic Substitution

Distinct regio- and enantioselectivity control in copper-catalyzed vinylogous and bisvinylogous propargylic substitution has been accomplished by using a novel chiral N,N,P ligand. The developed method provides an efficient and selective approach to an array of highly enantioenriched alkynyl unsaturated carbonyl compounds. Salient features include excellent functional group tolerance and broad substrate scope. The synthetic utility of the developed method is further demonstrated by a gram-scale synthesis and by application to a range of transformations including enantioselective synthesis of unique challenging compounds.

Synthesis of nitrogen-tethered 1,6-enynes through CuI/TFA catalysis

A new cascade process of the TFA-promoted Pictet–Spengler reaction and Cu-catalyzed intermolecular hydride transfer/alkynylation of an amine, formaldehyde solution, and an alkyne has been developed.