Facile, Direct Reaction of Benzaldehydes to 3-Arylprop-2-Enoic Acids and 3-Arylprop-2-Ynoic Acids in Aqueous Medium

Abstract

Wittig reactions of benzaldehydes, alkanals, and cycloalkanals as well as of acetophenones are carried out with alkoxycarbonyl methylidenetriphenylphosphoranes in 10 w% aqueous NaOH, where the cinnamates and alkenoates produced are hydrolysed in situ and the corresponding acids are obtained after mostly simple extractive work-up, often without employing organic solvents. Under the same conditions, benzaldehydes are reacted with alkoxycarbonyl bromomethylidenephosphorane to produce 3-arylprop-2-ynoic acids (arylpropiolic acids).

Carboxylation of styrenes with CBr4and DMSO via cooperative photoredox and cobalt catalysis

“…(E)-3-(3,4-Dimethoxyphenyl)acrylic acid (2j). 27 Following the general procedure using 3,4-dimethoxytyrene in place of styrene: white solid; 55 mg, 0. (1,3,3,3-Tetrabromopropyl)benzene (3a).…”

Tandem-, Domino- and One-Pot Reactions Involving Wittig- and Horner-Wadsworth-Emmons Olefination

“…Nevertheless, one-pot Wittig olefination-Claisen- [173], Wittig olefination-Cope- [169], and Wittig olefination-aza Wittig [176] rearrangement reactions have been published. Lastly, Wittig olefination and HWE reactions have been combined with functional group transformations, including the hydrolysis of an ester function [152] and the reduction of a carbonyl group [148]. Tandem-, Domino-and One-Pot Reactions Involving Wittig-and Horner-Wadsworth-Emmons... http://dx.doi.org/10.5772/intechopen.70364…”

“…NaOH, where the cinnamates formed are hydrolysed in situ to cinnamic acids 106 (Scheme 27) [152]. After completion of the reaction, triphenylphosphine oxide can be filtered off from the strongly basic, aqueous solution, and the cinnamic acids are isolated by simple filtration after acidification of the filtrate.…”

Natural and Synthetic Derivatives of Hydroxycinnamic Acid Modulating the Pathological Transformation of Amyloidogenic Proteins

“…The most common and straightforward methods for the synthesis of cinnamic acid itself is via the Perkin reaction [ 51 ] or Knoevenagel condensation [ 52 ] starting from benzaldehyde ( Figure 2 ). Even though the latter procedure can also be used for the synthesis of HCA derivatives, many other methods for constructing a cinnamoyl moiety have been also developed ( Figure 2 ), e.g., reaction of benzaldehydes with Meldrum’s acid in the presence of catalytic amounts of 2-carbamoylhydrazine-1-sulfonic acid and carbamoylsulfamic acid [ 53 ], Wittig olefination reaction of benzaldehydes [ 54 , 55 ], Heck coupling of aryl halides or benzoic anhydride with alkenes [ 56 ], and straightforward synthesis from aromatic aldehydes, aliphatic carboxylic acids and boron tribromide using 4-dimethylaminopyridine and pyridine as bases [ 57 ]. Here, we will focus only on synthetic methods for the preparation of HCAs and their derivatives.…”