Irregularities in the effect of potassium phosphate in ynamide synthesis.
The yields of ynamides using Hsung's second generation protocol depend substantially on the quality of K(3)PO(4). Samples of K(3)PO(4) from different suppliers were investigated by various techniques, revealing that the use of pure and anhydrous K(3)PO(4) provides higher ynamide yields in comparison to samples contaminated with hydrates (K(3)PO(4) x 1.5 H(2)O and K(3)PO(4) x 7 H(2)O). With high quality K(3)PO(4), a number of ynamides were synthesized in yields of 52-91%. In addition, we report that ynamides can undergo regioselective hydroamination with carbamates.
Dooleweerdt
Karin
K
Department of Chemistry and the Interdisciplinary Nanoscience Center, University of Aarhus, Langelandsgade 140, 8000 Aarhus C, Denmark.
Birkedal
Henrik
H
Ruhland
Thomas
T
Skrydstrup
Troels
T
D000480:Alkynes / Q000737:chemistry*; D000577:Amides / Q000737:chemistry*; D002219:Carbamates / Q000737:chemistry; D002384:Catalysis; D002625:Chemistry, Organic / Q000379:methods*; D003300:Copper / Q000737:chemistry; D008956:Models, Chemical; D010710:Phosphates / Q000737:chemistry*; D011188:Potassium / Q000737:chemistry; D017680:Potassium Compounds / Q000737:chemistry*; D013055:Spectrophotometry, Infrared / Q000379:methods; D013818:Thermogravimetry / Q000379:methods; D013997:Time Factors
D000480:Alkynes; D000577:Amides; D002219:Carbamates; D010710:Phosphates; D017680:Potassium Compounds; D003300:Copper; C013216:potassium phosphate; D011188:Potassium