25706-10-9Relevant academic research and scientific papers
Palladium-Catalyzed Regioselective Hydroaminocarbonylation of Alkynes to α,β-Unsaturated Primary Amides with Ammonium Chloride
Ji, Xiaolei,Gao, Bao,Zhou, Xibing,Liu, Zongjian,Huang, Hanmin
, p. 10134 - 10141 (2018)
α,β-Unsaturated primary amides have found numerous applications in drug development, organic materials, and polymer sciences. However, the catalytic synthesis of α,β-unsaturated primary amides via carbonylation of alkynes has long been an elusive endeavor. Here, we report a novel palladium-catalyzed hydroaminocarbonylation of alkynes with NH4Cl as the amine source, enabling the highly chemo- and regioselective synthesis of α,β-unsaturated primary amides. A variety of alkynes, including aromatic alkynes, aliphatic alkynes, terminal alkynes, internal alkynes, as well as diynes with various functional groups, react well. The method turns the parasitic noncoordination ability of ammonium salts into a strategic advantage, enabling the gram-scale reaction to be performed in the presence of 0.05 mol % of catalyst with excellent selectivity.
Hydroaminocarbonylation of Alkynes to Produce Primary α,β-Unsaturated Amides Using NH4HCO3 Dually as Ammonia Surrogate and Br?nsted Acid Additive
Wang, Dong-Liang,Guo, Wen-Di,Zhou, Qing,Liu, Lei,Lu, Yong,Liu, Ye
, p. 4264 - 4268 (2018/09/06)
By using NH4HCO3 dually as ammonia surrogate and Br?nsted acid additive, the production of primary α,β-unsaturated amides via hydroaminocarbonylation of alkynes was accomplished efficiently. The advantages of using the solid and inexpensive NH4HCO3 included: (1) the facile and clean manipulation without presence of stinky gaseous NH3 or liquids organic amines, (2) the inhibition of the subsequent dehydration and hydrolysis of amides due to its weak basicity, and (3) the facilitated formation of Pd?H catalytic active species by the released H2CO3 serving as a weak Br?nsted acid additive. In addition, the diphopshine of Dppp with the natural bite angle (βn) of 91° was found indispensable to spur the performance of the palladium catalyst for this reaction. Both terminal and internal phenylacetylene derivatives could be used as the substrates, affording the corresponding primary α,β-unsaturated amides in good yields along with excellent regio-selectivities to the branched ones.
