Phase Transfer Catalysis of Henry and Darzens Reactions

Abstract

We describe in this work the influence of the addition of phase transfer catalyst in heterogeneous medium liquid/liquid on the output of the reactions of Darzens and Henry. It proves that the reaction of Darzens is favoured in the presence of low base such as K<sub>2</sub>CO<sub>3</sub> and Et<sub>3</sub>N. Phase transfer catalysis is an efficient activation method in Darzens and Henry reactions. Thus, the Ethylene Diammonium Diacetate (EDD) has a comparable catalytic activity has that of quaternary ammonium salts in the reaction of Darzens

Gelatin Protein‐Mediated Direct Aldol Reaction

“…In contrast to our previous observations with the Henry (nitroaldol) reaction [10], the use of a phase transfer co-catalyst such as tetra-n-butylammonium bromide (TBAB) [12] did not improve the yield of the gelatin-mediated aldol reaction in water (entries 23). It is important to highlight that appropriate control experiments confirmed the catalytic activity of the protein.…”

C–C Bond formation catalyzed by natural gelatin and collagen proteins

“…Interestingly, the reaction could be also performed in water, although in this case the addition of a phase transfer cocatalyst (e.g., TBAB) was necessary to achieve comparable results (Table 1, entries 3 and 4) [18]. In pure water, the yield could be also improved to ca.…”

Oxygenophilic Lewis Acid Promoted Synthesis of 2-Arylindoles from Anilines and Cyanoepoxides in Alcohol

“…All oxirane-2-carbonitriles 1 were prepared with the literature reported method . To a solution of chloroacetonitrile (1.81 g, 24 mmol) or 2-chloropropanenitrile (2.15 g, 24 mmol) and KOH (1.35 g, 24 mmol) in 75 mL of THF was added an aldehyde (20 mmol) in one jet.…”