The Knoevenagel reaction is assisted by sodiumnitrate/fluorapatite in heterogeneous media. The reaction is carried out between an activated methylene and an aldehyde at room temperature without a solvent. The yields obtained are very high.
Nitrile biotransformations for the practical synthesis of highly enantiopure azido carboxylic acids and amides, ‘click’ to functionalized chiral triazoles and chiral β-amino acids
作者:Da-You Ma、De-Xian Wang、Qi-Yu Zheng、Mei-Xiang Wang
DOI:10.1016/j.tetasy.2006.08.021
日期:2006.9
(R)-12a underwent ‘click’ reactions with diethyl acetylenedicarboxylate and phenylacetylene to produce functionalized chiral triazoles 14 and 15, respectively. The easy preparation of the starting nitrile substrates, highlyefficient and enantioselective biotransformation reactions, and versatile utility of the resulting functionalized azido carboxylic acids and amidederivatives, render this method very
Natural phosphate doped with potassium fluoride and modified with sodium nitrate: efficient catalysts for the Knoevenagel condensation
作者:Saı̈d Sebti、Abdellatif Smahi、Abderrahim Solhy
DOI:10.1016/s0040-4039(02)00092-8
日期:2002.3
A high yield synthesis of activated alkenes is described using the inexpensive natural phosphate alone, doped with potassium fluoride or modified by sodium nitrate. The Knoevenagel condensation was carried out in mild conditions at room temperature in methanol. The catalytic activity of these phosphates are compared.
Uranyl nitrate hexahydrate performs as an efficient photocatalyst in the direct C–H to C–C bond conversion under blue light irradiation via hydrogen atom transfer (HAT). This uranyl salt enables the remarkable smooth functionalization of unactivated (cyclo)alkanes, ethers, acetals, and amides via radical addition onto electrophilic olefins. Dedicated electrochemical measurements on compounds and intermediates
New methods and reagents in organic synthesis. 41. Lithium trimethylsilyldiazomethane. A new synthon for the preparation of pyrazoles from α,β-unsaturated nitriles
作者:Tayahiko Aoyama、Sumie Inoue、Tokoyuki Shioiri
DOI:10.1016/s0040-4039(00)99904-0
日期:1984.1
Lithium trimethylsilyldiazomethane reacts smoothly with various α,β-unsaturated nitriles to give 3(or 5)-trimethylsilylpyrazoles in good yields.