20722-50-3Relevant academic research and scientific papers
Amine formylation via carbon dioxide recycling catalyzed by a simple and efficient heterogeneous palladium catalyst
Cui, Xinjiang,Zhang, Yan,Deng, Youquan,Shi, Feng
supporting information, p. 189 - 191 (2014/01/06)
A simple and efficient Pd/Al2O3-NR-RD catalyst was prepared by depositing palladium on a shape controllable Al2O 3-NR support through a two-step process that involves hydrothermal synthesis of Al2O3-NRs followed by reductive-deposition of palladium. This catalyst showed high activity in the catalytic formylation of amines by CO2-H2 under mild conditions with up to 96% yield.
Copper-diphosphine complex catalysts for N-formylation of amines under 1 atm of carbon dioxide with polymethylhydrosiloxane
Motokura, Ken,Takahashi, Naoki,Kashiwame, Daiki,Yamaguchi, Sho,Miyaji, Akimitsu,Baba, Toshihide
, p. 2392 - 2396 (2013/09/02)
N-formylation of a wide range of amines proceeded using copper-diphosphine complexes as homogeneous catalysts with polymethylhydrosiloxane (PMHS) under 1 atm of CO2. In the reaction of piperidine, for example, the turnover number (TON) reached 11700 in 23 h with 90% yield of the formylated product. This TON value is much higher than those of the reported catalysts for the formylation of amines under 1 atm of CO2 with hydrosilanes. The Cu complexes with phosphines having ortho-phenylene structures acted as good ligands for the formylation, as compared to a bidentate ligand connected with a propyl chain and a monodentate ligand. Among these diphosphines, ligands with alkyl functionalities, such as isopropyl and cyclohexyl groups, produced better results than the phenyl group. Not only cyclic secondary amines, but also linear secondary amines and aromatic and aliphatic primary amines were found to be reactive substrates. In the case of 2,2,6,6-tetramethylpiperidin-4-amine, the formylation proceeded regioselectively. A catalytic reaction pathway was proposed from a separate experiment using [Me2NCO2] [Me2NH2]. The Royal Society of Chemistry 2013.
Quenching of singlet oxygen by tertiary aliphatic amines. Structural effects on rates and products
Baciocchi, Enrico,Del Giacco, Tiziana,Lapi, Andrea
, p. 2273 - 2280 (2007/10/03)
A kinetic and product study of the reaction of a series of α-methyl-substituted N-methylpiperidines with thermally generated 1O2 in MeCN was carried out. It was found that as the number of α-methyl groups (Me in α-position relative to the N-atom) increases, the rate of 1O2 quenching (physical plus chemical) slightly decreases. This finding shows that, with respect to the reaction rate, steric effects are much more important than electronic effects as the latter should have produced the opposite result. The opposite outcome was instead found for the chemical quenching that leads to the N-demethylation products and N-formyl derivatives. The same trend was observed for the ratio between N-demethylation and formation of the N-formyl derivatives (NH/NCHO ratio). All these results are consistent with the mechanism reported in Scheme 1 where an exciplex is first formed that by a H-atom transfer process produces an α-amino-substituted C-radical. The latter forms the product of N-demethylation by one electron oxidation, or affords the N-formyl derivative by radical coupling (Scheme 1). Similar results were obtained with N,N-dimethylcyclohexanamine. However, this 'acyclic' amine exhibited behaviors quite distinct from those of the N-methylpiperidines series, with respect to reaction rate, extent of chemical quenching, and NH/NCHO ratio.
