title: NHC-Ag/Pd-Catalyzed Reductive Carboxylation of Terminal Alkynes with CO2and H2: A Combined Experimental and Computational Study for Fine-Tuned Selectivity.
abstract: Reductive carboxylation of terminal alkynes utilizing CO2and H2as reactants is an interesting and challenging transformation. Theoretical calculations indicated it would be kinetically possible to obtain cinnamic acid, the reductive carboxylation product, from phenylacetylene in a CO2/H2system with an N-heterocyclic carbene (NHC)-supported Ag/Pd bimetallic catalysts through competitive carboxylation/hydrogenation cascade reactions in one step. These calculations were verified experimentally with a poly-NHC-supported Ag/Pd catalyst. By tuning the catalyst composition and reaction temperature, phenylacetylene was selectively converted to cinnamic acid, hydrocinnamic acid, or phenylpropiolic acid in excellent yields.
authors.affiliation: Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos #04-01, Singapore, 138669, Singapore), Fax.
authors.forename: Dingyi
authors.initials: D
authors.lastname: Yu
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore.
authors.forename: Feng
authors.initials: F
authors.lastname: Zhou
authors.affiliation: Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos #04-01, Singapore, 138669, Singapore), Fax.
authors.forename: Diane S W
authors.initials: DS
authors.lastname: Lim
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore.
authors.forename: Haibin
authors.initials: H
authors.lastname: Su
authors.affiliation: Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos #04-01, Singapore, 138669, Singapore), Fax.
authors.forename: Yugen
authors.identifier: 0000-0002-8497-1175
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000480:Alkynes / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry; D002384:Catalysis; D006571:Heterocyclic Compounds / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D006865:Hydrogenation; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D010084:Oxidation-Reduction; D010165:Palladium / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*
chemical_list: D000480:Alkynes; D002264:Carboxylic Acids; D006571:Heterocyclic Compounds; D002245:Carbon Dioxide; C030011:carbene; D012834:Silver; D010165:Palladium; D006859:Hydrogen; D008697:Methane
keywords: Ag/Pd catalyst; CO2 utilization; H2 reduction; reductive carboxylation; terminal alkynes