Three Component syn-1,2-Arylmethylation of Internal Alkynes

Regioselective Twofold Annulation of Propargyl Acetates

The regioselective annulation of unsymmetrical alkynes has always been a focused research topic. A Pd-catalyzed double annulation of unsymmetrical alkynes (i.e., yne-acetates) with aryl diazonium salts for the synthesis of substituted naphthalene derivatives is developed. The process addresses intrinsic regioselectivity challenges in the annulations of unsymmetrical alkynes. Mechanistic investigations shed light on the crucial role of the acetate-directing groups in determining the regiochemical reaction outcome.

Copper-Catalyzed Regio- and Stereoselective Hydroarylation of Ynamide

Presented herein is a copper-catalyzed trans-hydroarylation of ynamides. The reaction showcases the assembly of boronic acids across the carbon-carbon triple bond of ynamides. The reaction proceeds under mild conditions offering a complementary approach for the versatile synthesis of multifunctional (E)-α,β-disubstituted enamides. Moreover, the hydroarylation process is highly regio- and stereoselective. The transformation shows a broad scope (30 examples) and tolerates a wide range of labile functional groups. Control experiments provide substantive evidence supporting the mechanistic cycle and the observed selectivity.