We report a copper-catalyzed alkynylation of azadipeptides using ethynylbenziodoxolone (EBX) reagents. Non-symmetrical ynehydrazides could be obtained in 25-97% yield using azaglycine derivatives as nucleophiles. The transfor-mation is compatible with most functional groups naturally occurring on amino acid side-chains and allows the transfer of silyl-, alkyl- and aryl-substituted alkynes. The obtained α-alkynyl azaglycine products could be further functionalized by nucleophilic attack or cycloaddition on the triple bond.
Conditions to hydrolyze the hydrazone on functionalized products were added in Scheme 4. The experimental procedure and characterization data for this reaction were added to the SI, and a cover page was added to the SI.