title: A Simple Zinc Catalyst for Carbamate Synthesis Directly from CO2.
abstract: Several zinc salts were employed as catalysts for the synthesis of carbamates directly from aromatic amines, CO2, and silicate esters. Zn(OAc)2offered the best performance among the salts tested. The addition of an N-donor ligand such as 1,10-phenanthroline increased the yield. The best catalytic performance of Zn(OAc)2can be explained by carboxylate-assisted proton activation. The interaction between the substrate and the catalyst can be observed by chemical shifts in1H and15N NMR spectra. Isocyanate was a key intermediate, which was generated from amine and CO2. Silicate ester was finally converted to siloxane, which was determined by29Si NMR. The commercially available catalyst system could be reused. The yield of isolated carbamate could reach up to 96 % with various substrates, and the catalytic reaction was amine-selective in the presence of other functional groups.
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8565, Japan.
authors.forename: Qiao
authors.identifier: 0000-0002-6326-2556
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8573, Japan.
authors.forename: Hao-Yu
authors.initials: HY
authors.lastname: Yuan
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8565, Japan.
authors.forename: Norihisa
authors.initials: N
authors.lastname: Fukaya
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8565, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yasuda
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8565, Japan.|Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8573, Japan.
authors.forename: Jun-Chul
authors.identifier: 0000-0002-7049-5032
authors.initials: JC
authors.lastname: Choi
mesh_terms: D000588:Amines / Q000737:chemistry; D002219:Carbamates / Q000138:chemical synthesis* / Q000737:chemistry; D002245:Carbon Dioxide / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry; D002384:Catalysis; D060326:Chemistry Techniques, Synthetic; D017640:Silicates / Q000737:chemistry; D015032:Zinc / Q000737:chemistry*
chemical_list: D000588:Amines; D002219:Carbamates; D002264:Carboxylic Acids; D017640:Silicates; D002245:Carbon Dioxide; D015032:Zinc
keywords: C1 building blocks; carbamates; carbon dioxide fixation; synthetic methods; zinc