Natural Phosphate Doped with Potassium Fluoride:  Efficient Catalyst for the Construction of a Carbon−Carbon Bond

Abstract

Natural phosphate-doped catalyst was found to be an efficient, environmentally attractive, and selective solid base catalyst for 1,4-Michael addition. The products of undesirable side reactions resulting from 1,2-adddition, polymerization, and bis-addition are not observed. The workup procedure is simplified by simple filtration with the use of natural phosphate alone or doped with potassium fluoride. Potassium fluoride-doped natural phosphate is used as catalyst for a facile synthesis of 4H-chromene under heterogeneous conditions.

Potassium Fluoride/ K10-montmorillonite Nanostructure as a Green and Reusable Catalyst Under mild Reaction Conditions for the Knovenagel Condensation

“…A lot of supports have been introduced for increasing the basicity of KF such as KF/ZnO, KF/Ca-Mg-Al, KF/ CaO-Fe 3 O 4 , KF/celite, KF/zeolite, and KF/LDH mainly applied for organic production. Although, a majority of the abovementioned solid bases are effective in organic transformations, they suffer from some drawbacks such as low basicity, use of expensive solid supports and tedious preparation steps [17][18][19][20][21][22][23][24][25] . Montmorillonite (MMT) clay having two silica tetrahedral sheets layered between one alumina octahedral sheets.…”

Catalysis by phosphates: A simple and efficient procedure for transesterification reaction

“…Thus ZnCl 2 /NP has been used as excellent acidic catalyst for Friedel-Crafts alkylation [6], 1,3-dipolar cycloaddition [7], acyclonucleoside synthesis [8] and 3,4-dihydropyrimdin-2(1H)-one synthesis [9]. KF/NP catalyzed efficiently nitrile hydration [10], Michael addition [4,[11][12][13], Knoevenagel condensation [5,14], flavanone synthesis [15], nucleobase alkylation [16] and nucleoside synthesis [17]. On the other hand, we have demonstrated that Na/NP, as strongly basic catalyst, can promote Knoevenagel condensation [14], alkene epoxidation [18], Claisen-Schmidt condensation [19,20] and Michael addition [21].…”

Visible light induced Knoevenagel condensation: A clean and efficient protocol using aqueous fruit extract of tamarindus indica as catalyst

“…It has been suggested that the effect of water on organic reaction may be due to the high internal pressure exerted by a water solution which results from the high cohesive energy of water [42]. In literature, a number of organic reactions using natural catalysts such as clay [43][44][45][46], natural phosphates [47][48][49], animal bone [50], and various fruit juices are reported. Due to acidic nature aqueous fruit juice like lemon [51][52][53][54][55][56][57], pineapple [58], [59], coconut [60], Acacia concinna [61], Sapindus trifolistus [62] and Tamarindus indica [63] fruit has been found to be a suitable replacement for various homogeneous acid catalysts.…”