92356-72-4Relevant articles and documents
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 (2000)
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.
Ruthenium-Catalyzed Oxidative Cross-Coupling Reaction of Activated Olefins with Vinyl Boronates for the Synthesis of (E, E)-1,3-Dienes
Dethe, Dattatraya H.,Beeralingappa, Nagabhushana C.,Uike, Amar
, p. 3444 - 3455 (2021/02/16)
An oxidative cross-coupling reaction between activated olefins and vinyl boronate derivatives has been developed for the highly stereoselective construction of synthetically useful (E,E)-1,3-dienes. The highlight of this reaction is that exclusive stereoselectivity (only E,E-isomer) was achieved from a base-free, ligand-free, and mild catalytic condition with a less expensive [RuCl2(p-cymene)]2 catalyst.
Microwave-accelerated Ru-catalyzed hydrovinylation of alkynes and enynes: A straightforward approach toward 1,3-dienes and 1,3,5-trienes
Schabel, Tobias,Plietker, Bernd
, p. 6938 - 6941 (2013/06/27)
Quick, but not dirty! Microwave heating was found to have a significant effect on the Ru-catalyzed hydrovinylations of alkynes. A broad range of different terminal alkynes were coupled to methyl acrylate within just 30min in good to excellent yields (see scheme). This new protocol was transferred to the hydrovinylation of enynes as novel coupling partners in C-H-activation chemistry giving different 1,3,5-trienes as the sole products. Copyright
Synthetic and spectroscopic studies of structural analogs of piper amides - The 5-aryl-2E,4E-pentadienamides
Banerji, Avijit,Banerjee, Tapasri,Sengupta, Ratna,Sengupta, Piyali,Das, Chittaranjan,Sahu, Anita
, p. 876 - 883 (2007/10/03)
The methyl esters and piperidides of fourteen 5-aryl-2E,4E-pentadienoic acids have been synthesized starting from the corresponding aryl aldehydes.
Substituent Effects on Carbon-13 NMR Chemical Shifts of Side-chain Carbons in 5-Aryl-2E,4E-pentadienoic Acid Derivatives
Banerji, Avijit,Ghosal, Tapasree,Acharyya, Aditi K.
, p. 546 - 549 (2007/10/02)
The 13C NMR spectra of two series of 5-aryl-2E,4E-pentadienoic acid derivatives, viz. the methyl esters and piperidides have been determined.The chemical shifts of C-2 and C-4 show very good correlations with the Hammett ?+-constants for all the substituents investigated, except for the para-nitro group which is capable of excerting a strong -R effect.A possible explanation for this has been advanced.Hammett correlations between substituents and the chemical shifts of both C-3 and C-5 carbons using ?0 parameters are less satisfactory.A reverse chemical shift effect has been observed for these two centres.
