(2<i>S</i>,5<i>R</i>)-2-Methylaminomethyl-1-methyl-5-phenylpyrrolidine, a chiral diamine ligand for copper(<scp>ii</scp>)-catalysed Henry reactions with superb enantiocontrol
作者:Dagmar Scharnagel、Felix Prause、Johannes Kaldun、Robert G. Haase、Matthias Breuning
DOI:10.1039/c4cc02429j
日期:——
Copper(ii)-complexes of a cis-2-aminomethyl-5-phenylpyrrolidine catalyse enantioselective Henry reactions with extraordinarily high stereocontrol.
Base-catalyzed reactions enhanced by solid acids: Amine-catalyzed nitroaldol (Henry) reactions enhanced by silica gel or mesoporous silica SBA-15
作者:Kiyoshi Tanemura、Tsuneo Suzuki
DOI:10.1016/j.tetlet.2017.12.050
日期:2018.1
The reactions of various aldehydes with CH3NO2 catalyzed by Et3N, n-C6H13NH2, and Me2N(CH2)2NH2 were accelerated by the addition of silica gel to givearomatic (aliphatic) β-nitroalcohols, aromatic nitroalkenes, and aromatic 1,3-dinitroalkanes, respectively. Mesoporous silica SBA-15 showed higher activity than silica gel for the synthesis of aromatic nitroalkenes by the reactions of the corresponding
Vasicine from Adhatoda vasica as an organocatalyst for metal-free Henry reaction and reductive heterocyclization of o-nitroacylbenzenes
作者:Sushila Sharma、Manoranjan Kumar、Vinod Bhatt、Onkar S. Nayal、Maheshwar S. Thakur、Neeraj Kumar、Bikram Singh、Upendra Sharma
DOI:10.1016/j.tetlet.2016.09.095
日期:2016.11
Vasicine, a quinazolinealkaloid, from the leaves of Adhatodavasica, has been utilized as an efficient catalyst for metal and base free Henry reaction of various aldehydes with nitro alkanes. The method can be used in the synthesis of various β-nitro alcohols under mild reaction conditions without use of hazardous organic solvents and expensive catalysts. Vasicine is also applied successfully for
DMSO and in water in the presence of tetrabutylammonium bromide (TBAB) as a phase transfer catalyst. Negligible background reactions (i.e., negative control experiment in the absence of keratin protein) were observed in these solvent systems. Aromatic aldehydes bearing electron-donating groups and aliphatic aldehydes showed poor or no conversion, respectively. In general, the reactions in water/TBAB
Crown Ether Complex Cation Ionic Liquids: Preparation and Applications in Organic Reactions
作者:Yingying Song、Huanwang Jing、Bo Li、Dongsheng Bai
DOI:10.1002/chem.201100112
日期:2011.7.25
cation ionicliquids (CECILs) were designed, synthesised and characterised by NMR spectroscopy, HRMS, thermogravimetric differential thermal analysis (TG‐DTA) and elemental analysis. Their applications in various organic reactions were investigated: [15‐C‐5Na][OH], [15‐C‐5Na][OAc], [18‐C‐6K][OH] and [18‐C‐6K][OAc] (15‐C‐5=[15]crown‐5; 18‐C‐6=[18]crown‐6) efficiently catalysed the Michael addition of alkenes