2314-80-9Relevant articles and documents
Reduction of Activated Alkenes by PIII/PV Redox Cycling Catalysis
Longwitz, Lars,Werner, Thomas
supporting information, p. 2760 - 2763 (2020/02/05)
The carbon–carbon double bond of unsaturated carbonyl compounds was readily reduced by using a phosphetane oxide catalyst in the presence of a simple organosilane as the terminal reductant and water as the hydrogen source. Quantitative hydrogenation was observed when 1.0 mol % of a methyl-substituted phosphetane oxide was employed as the catalyst. The procedure is highly selective towards activated double bonds, tolerating a variety of functional groups that are usually prone to reduction. In total, 25 alkenes and two alkynes were hydrogenated to the corresponding alkanes in excellent yields of up to 99 %. Notably, less active poly(methylhydrosiloxane) could also be utilized as the terminal reductant. Mechanistic investigations revealed the phosphane as the catalyst resting state and a protonation/deprotonation sequence as the crucial step in the catalytic cycle.
Efficient copper-catalyzed N-arylation of NH-containing heterocycles and sulfonamides with arenediazonium tetrafluoroborates
Ouyang, Yu-Qing,Yang, Zhen-Hua,Chen, Zhong-Hui,Zhao, Sheng-Yin
, p. 771 - 778 (2017/04/06)
A practical copper-catalyzed N-arylation of NH-containing heterocycles with arenediazonium tetrafluoroborates has been developed using CuCl as catalyst and K2CO3 as additive under ligand-free conditions. This reaction system has wide substrate scope including imides, 1H-pyrazole, 1H-tetrazoles, 1,2-benzisothiazol-3(2H)-one, and related sulfonamides and gives moderate to excellent yields (up to 95%) of the desired products. This strategy is very general, simple, environmentally friendly, and tolerant of oxygen.
Direct Synthesis of Cyclic Imides from Carboxylic Anhydrides and Amines by Nb2O5 as a Water-Tolerant Lewis Acid Catalyst
Ali, Md. A.,Moromi, Sondomoyee K.,Touchy, Abeda S.,Shimizu, Ken-Ichi
, p. 891 - 894 (2016/03/15)
In the 20 types of heterogeneous and homogenous catalysts screened, Nb2O5 showed the highest activity for the synthesis of N-phenylsuccinimide by dehydrative condensation of succinic anhydride and aniline. Nb2O5 was used in the direct imidation of a wide range of carboxylic anhydrides with NH3 or amines with various functional groups and could be reused. Kinetic studies showed that the Lewis acid Nb2O5 catalyst was more water tolerant than both the Lewis acidic oxide TiO2 and the homogeneous Lewis acid ZrCl4, which resulted in higher yields of imides through the use of Nb2O5. Int-imidation tactics: A general method for the direct synthesis of cyclic imides from cyclic anhydrides with amines (or ammonia) under solvent-free conditions is reported. Kinetic studies indicate that the Lewis acid sites of Nb2O5 are highly water tolerant, which results in high catalytic activity for imidation even in the presence of water formed during the reaction. The catalyst can be recovered and reused four times without a marked decrease in yield.