56189-94-7Relevant academic research and scientific papers
Synthesis of 4-methyldienoates using a vinylogous horner-wadsworth-emmons reagent. application to the synthesis of trichostatic acid
Markiewicz, John T.,Schauer, Douglas J.,Loefstedt, Joakim,Corden, Steven J.,Wiest, Olaf,Helquist, Paul
supporting information; experimental part, p. 2061 - 2064 (2010/06/16)
Chemical Equation Presented The utility of the unsaturated phosphonate 1 as a vinylogous Horner-Wadsworth-Emmons reagent was explored in reactions with, aldehydes affording 4-methyldienoate esters. Factors that affect E/Z selectivity were studied. A simplified synthesis of trichostatic acid 3 was accomplished, to demonstrate utility of this reagent.
Catalytic Hunsdiecker reaction and one-pot catalytic Hunsdiecker-Heck strategy: Synthesis of α,β-unsaturated aromatic halides, α- (dihalomethyl)benzenemethanols, 5-aryl-2,4-pentadienoic acids, dienoates and dienamides
Naskar, Dinabandhu,Roy, Sujit
, p. 1369 - 1377 (2007/10/03)
The reaction of α,β-unsaturated aromatic (or heteroaromatic) carboxylic acids with N-halosuccinimides (1 equiv.) and catalytic tetrabutylammonium trifluoroacetate (0.2 equiv.) in dichloroethane results in facile halodecarboxylation affording the corresponding (E)-halides in good to excellent yields. A similar reaction, but with 2 equiv. of N-halosuccinimides in acetonitrile-water (1:1 v/v) results in the exclusive formation of the corresponding α-(dihalomethyl)benzenemethanols. Furthermore, a one-pot strategy has been developed combining catalytic Hunsdiecker reaction (using tetrabutylammonium trifluoroacetate in dichloroethane) and Heck coupling (using palladium acetate/triethylamine/triphenylantimony/dichloroethane) for the synthesis of 5-aryl-2,4-pentadienoic acids, esters and amides in moderate to good yields. The natural product piperine and pipergualamine has been synthesized via the above route. Mechanistic and theoretical studies (via AM1 calculations) provide a useful insight into the mechanism of the present halodecarboxylation reaction, suggesting an ionic pathway involving the attack of the halogenium ion across the carbon-carbon double bond, triggering the elimination of carbon dioxide. (C) 2000 Elsevier Science Ltd.
