At 200 ℃ and 50 mPa, the oxidative carbonylation of amines catalyzed by organic gold complexes HAuCl 4, Au(PPh 3)Cl, Au(PPh 3) 2Cl, Au(PPh 3)NO 3 and [Au(PPh 3)] 2S afforded R(NHCO 2CH 3) n with a high conversion and...At 200 ℃ and 50 mPa, the oxidative carbonylation of amines catalyzed by organic gold complexes HAuCl 4, Au(PPh 3)Cl, Au(PPh 3) 2Cl, Au(PPh 3)NO 3 and [Au(PPh 3)] 2S afforded R(NHCO 2CH 3) n with a high conversion and selectivity. The best results were obtained when using the catalyst Au(PPh 3)Cl in the presence of PPh 3. The catalytic efficiency of catalytic Au(PPh 3)Cl was compared to Pd(PPh 3) 2Cl 2, e.g. the conversion was 97.2% and selectivity was 89% when using catalyst Au(PPh 3)Cl in the presence of PPh 3, while the conversion was 98.8% and selectivity was 86% when using catalyst Pd(PPh 3) 2Cl 2 in the presence of PPh 3. The experimental results suggested that Au complexes might be promising catalysts instead of Pd catalysts for the oxidative carbonylation of amines to carbamates.展开更多
Novel combined PdCl 2(RuCl 3) with ZrO 2 SO 3 catalysts were developed for the synthesis of carbamates by oxidative carbonylation of aliphatic and aromatic amines. At 170 ℃ and 4.0 MPa, oxidative carbonylation of aro...Novel combined PdCl 2(RuCl 3) with ZrO 2 SO 3 catalysts were developed for the synthesis of carbamates by oxidative carbonylation of aliphatic and aromatic amines. At 170 ℃ and 4.0 MPa, oxidative carbonylation of aromatic amines to the corresponding carbamates over this catalyst system could be proceeded with a high conversion and selectivity. Especially when β naphthylamine was used as the substrate, 100% conversion and 95% selectivity were obtained in only 15 min. The catalytic performance of PdCl 2/ZrO 2 SO 3 was better than that of RuCl 3/ZrO 2 SO 3 for such oxidative carbonylation reaction. Possible role of ZrO 2 SO 3 as co catalyst was also conjectured.展开更多
In this paper, it is first confirmed using NMR method, that amino acids have one or more active groups which can react with Br2 in the oscillating reaction of amino acids. They are -NH2、 -OH、 -SH and heterocyclic gr...In this paper, it is first confirmed using NMR method, that amino acids have one or more active groups which can react with Br2 in the oscillating reaction of amino acids. They are -NH2、 -OH、 -SH and heterocyclic group of the amino acids. These active groups constitute the activation centre of the oscillating reaction. An important conclusion is that the activation centre controls the oscillating reaction and the oscllating lifetime.展开更多
文摘At 200 ℃ and 50 mPa, the oxidative carbonylation of amines catalyzed by organic gold complexes HAuCl 4, Au(PPh 3)Cl, Au(PPh 3) 2Cl, Au(PPh 3)NO 3 and [Au(PPh 3)] 2S afforded R(NHCO 2CH 3) n with a high conversion and selectivity. The best results were obtained when using the catalyst Au(PPh 3)Cl in the presence of PPh 3. The catalytic efficiency of catalytic Au(PPh 3)Cl was compared to Pd(PPh 3) 2Cl 2, e.g. the conversion was 97.2% and selectivity was 89% when using catalyst Au(PPh 3)Cl in the presence of PPh 3, while the conversion was 98.8% and selectivity was 86% when using catalyst Pd(PPh 3) 2Cl 2 in the presence of PPh 3. The experimental results suggested that Au complexes might be promising catalysts instead of Pd catalysts for the oxidative carbonylation of amines to carbamates.
文摘Novel combined PdCl 2(RuCl 3) with ZrO 2 SO 3 catalysts were developed for the synthesis of carbamates by oxidative carbonylation of aliphatic and aromatic amines. At 170 ℃ and 4.0 MPa, oxidative carbonylation of aromatic amines to the corresponding carbamates over this catalyst system could be proceeded with a high conversion and selectivity. Especially when β naphthylamine was used as the substrate, 100% conversion and 95% selectivity were obtained in only 15 min. The catalytic performance of PdCl 2/ZrO 2 SO 3 was better than that of RuCl 3/ZrO 2 SO 3 for such oxidative carbonylation reaction. Possible role of ZrO 2 SO 3 as co catalyst was also conjectured.
文摘In this paper, it is first confirmed using NMR method, that amino acids have one or more active groups which can react with Br2 in the oscillating reaction of amino acids. They are -NH2、 -OH、 -SH and heterocyclic group of the amino acids. These active groups constitute the activation centre of the oscillating reaction. An important conclusion is that the activation centre controls the oscillating reaction and the oscllating lifetime.
