Named Organic Reactions

Synthesis of Novel Pyrazolylmethylene-Pyrimidine Heterocycles: Potential Synthons for Hybrid Β-Lactams

“…Literature survey has revealed that Knoevenagel condensation [19] is generally carried out in the presence of organic bases such as aliphatic amines, ethylene diamine, piperidine or their corresponding ammonium salts and amino acids [20,21]. Apart from this, use of various other Lewis acid and base catalysts such as ZnCl 2 , CdI 2 , Al 2 O 3 , KF/Al 2 O 3 , MgF has been reported in the literature [22][23][24][25][26].…”

Green Chemistry – Aspects for the Knoevenagel Reaction

“…Knoevenagel condensation is a classic C-C bond formation reaction in organic chemistry (Laue & Plagens, 2005). These condensations occur between aldehydes or ketones and active methylene compounds with ammonia or another amine as a catalyst in organic solvents (Knoevenagel, 1894).…”

“…The Knoevenagel reaction is considered to be a modification of the aldol reaction; the main difference between these approaches is the higher acidity of the active methylene hydrogen when compared to an -carbonyl hydrogen (Smith & March, 2001). Figure 1 illustrates the condensation of a ketone (1) with a malonate compound (2) to form the Knoevenagel condensation product (3), which is then used to form the ,-unsaturated carboxylic compounds (3) and (4) (Laue & Plagens, 2005). Subsequent to the first description of the Knoevenagel reaction, changes were introduced using pyridine as the solvent and piperidine as the catalyst, which was named the Doebner Modification (Doebner, 1900).…”

Use of Protease from Bacillus licheniformis as Promiscuous Catalyst for Organic Synthesis: Applications in CC and CN Bond Formation Reactions

“…C À N Bond Formation by Michael-Type Additions: Michael type additions are fundamental transformations in organic synthesis for the formation of carbonheteroatom bonds with a perfect atom economy. [31] Some years ago, our research group discovered the promiscuous aza-Michael reaction between secondary amines and acrylonitrile using different CAL-B preparations. [32] Similarly, the catalytic promiscuous efficiencies of other lipases such as lipase TL, lipase RM, Candida cylindracea lipase or Pseudomonas cepacia lipase (currently known as Burkholderia cepacia lipase) have been recently demonstrated by the addition of different primary and secondary amines to acrylonitrile or alkyl acrylates.…”