Synthesis of aryl α-keto-acids via the Cu-catalyzed conversion of aryl nitroaldol products
摘要:
Cu(II) salts efficiently catalyze the conversion of a variety of aryl nitroaldol products to afford the corresponding aryl alpha-keto-acids in high yields using 30% aq. AcOH:MeOH (1:1) as the solvent. (C) 2000 Elsevier Science Ltd. All rights reserved.
(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.
铜(II)配合物与顺式-2-氨基甲基-5-苯基吡咯烷催化了具有极高立体控制性的对映选择性亨利反应。
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
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
Preparation of indium nitronates and their Henry reactions
作者:Raquel G. Soengas、Rita Acúrcio、Artur M. S. Silva
DOI:10.1039/c4ob01468e
日期:——
Indium nitronates were readily prepared from commercially available nitroalkanes by transmetallation of the corresponding lithium nitronates with indium salts. The Henryreaction of this indium organometallics with aldehydes afforded β-nitroalkanols in moderate to high yields. The use of chiral sugar aldehydes furnished the corresponding carbohydrate-derived β-nitroalkanols with excellent stereoselectivity
Copper Complex of Aminoisoborneol Schiff Base Cu
<sub>2</sub>
(SBAIB‐d)
<sub>2</sub>
: An Efficient Catalyst for Direct Catalytic Asymmetric Nitroaldol (Henry) Reaction
new bifunctional coppercomplex of the aminoisoborneolSchiffbase – Cu2(SBAIB‐d)2 – has been developed for the effective directcatalyticasymmetricHenryreaction. One mol% of this catalyst produces the expected Henry products in high yields (up to 99%) with excellent enantioselectivities (up to 98% ee). The utility of the present catalyst was also extended to the Henryreaction with nitroethane