Copper(II)-catalyzed amidations of alkynyl bromides as a general synthesis of ynamides and Z-enamides. An intramolecular amidation for the synthesis of macrocyclic ynamides.

A general and efficient method for the coupling of a wide range of amides with alkynyl bromides is described here. This novel amidation reaction involves a catalytic protocol using copper(II) sulfate-pentahydrate and 1,10-phenanthroline to direct the sp-C-N bond formation, leading to a structurally diverse array of ynamides including macrocyclic ynamides via an intramolecular amidation. Given the surging interest in ynamide chemistry, this atom economical synthesis of ynamides should invoke further attention from the synthetic organic community.

Syntheses of 2,5-disubstituted dihydrofurans from gamma-substituted chiral allenamides.

[reaction: see text] Details of a synthesis of dihydrofurans using gamma-substituted chiral allenamides are described here. Some transformations of these dihydrofurans are also examined including a highly stereoselective dihydroxylation and a rare account of a Lewis acid-mediated removal of an N-acyl substituent at the anomeric carbon of a tetrahydrofuran ring system. These studies provide further support for the synthetic utility of allenamides.