发现Mg-Al-O- t -Bu水滑石催化剂是一种有效的,对环境有吸引力的,对1,4迈克尔加成反应有选择性的固体碱催化剂。Mg–Al–O– t – Bu水滑石通过Knoevenagel缩合反应将相应的活化羧酸酯或腈与各种醛缩合,对于简单合成α,β-不饱和酯和腈也有效。这些反应在室温下以Mg–Al–O– t – Bu水滑石的存在速率比在其他任何催化剂存在下的速率更高。
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.
Synthesis of cyclopropane-1,1,2,2-tetracarboxylic acid derivatives from aldehydes and CH-acids in the K2CO3/Bun 4NPF6/toluene heterogeneous system
作者:G. V. Kryshtal、G. M. Zhdankina、S. G. Zlotin
DOI:10.1007/s11172-011-0349-7
日期:2011.11
A one-pot method for the synthesis of cyclopropane-1,1,2,2-tetracarboxylic derivatives was developed starting from aldehydes and cyanoacetic and 2-bromomalonic esters under heterogeneous conditions (K2CO3/PhMe) in the presence of recoverable phase-transfer catalyst Bun 4NPF6.
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.
Ammonium Chloride: An Efficient and Environmentally benign Catalyst for
Knoevenagel Condensation of Carbonyl and Active Methylene Compounds
作者:S. Tasqeeruddin、Yahya I. Asiri、M. Mujahid A lam
DOI:10.14233/ajchem.2020.22879
日期:——
In the present study, a rapid, simple and an efficient procedure for the Knoevenagel condensation of various carbonyl and activemethylenecompounds in ethanol at a moderate temperature in the presence of a catalytic amount of an efficient, environmentally benign and inexpensive ammonium chloride is reported. Simple reaction procedure, economic and ecofriendly catalyst, mild reaction conditions and
Asymmetric Michael Reaction of Aldehydes and α‐Cyano α,β‐Unsaturated Esters Catalyzed by Diphenylprolinol Silyl Ether; a Facile Asymmetric Route to 3,4,5‐Trisubstituted Piperidines
A highly enantioselective diphenylprolinol silyl ether‐mediated asymmetric Michael reaction of a variety of aldehydes and β‐substituted α‐cyano α,β‐unsaturated esters was developed. The organocatalytic conjugate addition provided synthetically useful chiral adducts possessing three consecutive stereocenters and suitably oriented functional handles that were readily transformed via a sequence of reductive‐cyclization