Copper‐Catalyzed Synthesis of Terminal vs. Fluorine‐Substituted N‐Allenamides via Addition of Diazo Compounds to Terminal Ynamides

Abstract

A copper-mediated coupling reaction between ynamides and diazo-compounds to produce N-allenamides is reported for the first time. This method enables facile and rapid access to terminal N-allenamides by using commercially available TMS-diazomethane with wide functional group compatibility on the nitrogen. Furthermore, the ubiquity of [a

One-Pot anti-Michael Regio- and Stereoselective Hydroamination of Activated N-Allenamides

“…We recently reported an efficient protocol for the synthesis of N-allenamides through a copper-catalyzed addition of TMSdiazomethane to ynamides. 10 Notably, Hsung et al reported a rhodium-catalyzed addition of ethyl diazoacetate to ynamides, affording exclusively furans, albeit in a poor yield. 11 Taking into account our previous work, we envisioned the addition of ethyl diazoacetate to ynamides under copper catalysis.…”

Silver-Catalyzed Domino Reaction of CF3-Substituted N-Allenamides with Primary Amines for the Construction of 2-Amido-5-fluoropyrroles

“…In view of the limited approaches for the incorporation of fluorine on pyrroles and our interest in ynamide chemistry, we envisioned that gem -difluorinated ene-ynamides could be employed to generate fluorinated pyrroles via hydroamination followed by cyclization.…”

Regio- and Stereoselective Addition to gem-Difluorinated Ene–Ynamides: Access to Stereodefined Fluorinated Dienes

“…19 (Scheme 1, e) The difluorovinyl pharmacophore part was also prepared via a Wittig-type reaction from carbonyl compounds (Scheme 1, f). 20 With regard to our previous work on N-allenamides 21 and ynamides, 22 we became interested in whether trifluoromethylated N-allenamides could be employed to generate ene-ynamides.…”

“…Trifluoromethylated N-allenamides were obtained by treatment of terminal ynamides with trifluoromethylated diazomethane according to our previously developed strategy. 21 We initiated our base-induced study by treatment of N-allenamide 1a with NaH. The formation of the first difluorinated ene− ynamide 2a was observed in 57% yield (Table 1, entry 1).…”

“…With regard to our previous work on N -allenamides and ynamides, we became interested in whether trifluoromethylated N -allenamides could be employed to generate ene–ynamides.…”