The silylzincation of terminal ynamides is achieved through a radical‐chain process involving (Me3Si)3SiH and R2Zn. A potentially competing polar mechanism is excluded on the basis of diagnostic control experiments. The unique feature of this addition across the CC bond is its trans selectivity. One‐pot electrophilic substitution of the CZn bond by CuI‐mediated CC bond formation and subsequent manipulation
Copper-Catalyzed Aerobic Oxidative Amidation of Terminal Alkynes: Efficient Synthesis of Ynamides
作者:Tetsuya Hamada、Xuan Ye、Shannon S. Stahl
DOI:10.1021/ja077406x
日期:2008.1.1
A copper-catalyzed method for the preparation of ynamides has been identified that proceeds via aerobicoxidative coupling of terminal alkynes with various nitrogen nucleophiles, including cyclic carbamates, amides and ureas, and N-alkyl-arylsulfonamides and indoles.
diazo-compounds was developed. DFT calculations showed that this transformation relies on an uncommon, reversed mechanism that, regardless of the polarization of the ynamide, favors the addition of the diazo compound at the β-position of the ynamide. The protocol tolerates a wide range of functional groups. This copper-catalyzed process represents the first synthesis of tri-, di- or per-fluorinated N-allenamides