56453-88-4Relevant academic research and scientific papers
Semireduction of alkynoic acids via a transition metal-free α borylation-protodeborylation sequence
Verma, Astha,Grams, R. Justin,Rastatter, Brett P.,Santos, Webster L.
supporting information, p. 2113 - 2117 (2019/02/25)
A method for the semi-reduction of alkynoic acids through an α-borylation and subsequent protodeborylation mechanism has been developed. The transition metal-free protocol is achieved through the activation of bis(pinacolato)diboron by an in situ generated carboxylate moiety yielding aryl acrylic acids. Our studies demonstrate an unprecedented dual role for the carboxylate anion that involves the activation of the diboron reagent and a directing effect in the α-borylation.
Key structural features of cis-cinnamic acid as an allelochemical
Abe, Masato,Nishikawa, Keisuke,Okuda, Katsuhiro,Shindo, Mitsuru,Fukuda, Hiroshi,Nakanishi, Kazunari,Tazawa, Yuta,Taniguchi, Tomoya,Park, So-Young,Hiradate, Syuntaro,Fujii, Yoshiharu
, p. 56 - 67,12 (2012/12/12)
1-O-cis-cinnamoyl-β-d-glucopyranose is one of the most potent allelochemicals isolated from Spiraea thunbergii Sieb. It is suggested that it derives its strong inhibitory activity from cis-cinnamic acid, which is crucial for phytotoxicity. It was synthesized to confirm its structure and bioactivity, and also a series of cis-cinnamic acid analogues were prepared to elucidate the key features of cis-cinnamic acid for lettuce root growth inhibition. The cis-cyclopropyl analogue showed potent inhibitory activity while the saturated and alkyne analogues proved to be inactive, demonstrating the importance of the cis-double bond. Moreover, the aromatic ring could not be replaced with a saturated ring. However, the 1,3-dienylcyclohexene analogue showed strong activity. These results suggest that the geometry of the C-C double bond between the carboxyl group and the aromatic ring is essential for potent inhibitory activity. In addition, using several light sources, the photostability of the cinnamic acid derivatives and the role of the C-C double bond were also investigated.
A short and convenient preparation of (E)-3-(1-cyclohexenyl)-2- propenoic acid using a palladium(II) complex-catalyzed olefination
Lai, Gaifa,McAllister, Timothy
, p. 409 - 413 (2007/10/03)
A convenient, three-step preparation of (E)-3-(1-cyclohexenyl)-2- propenoic acid (1) from cyclohexanone was developed, which exploited the palladium(II) complex-catalyzed olefination of the triflate 3 as a key step.
Nickel-mediated regio- and chemoselective carboxylation of alkynes in the presence of carbon dioxide
Saito, Shinichi,Nakagawa, Satomi,Koizumi, Toru,Hirayama, Kyoko,Yamamoto, Yoshinori
, p. 3975 - 3978 (2007/10/03)
Alkynes are carboxylated in a highly regio- and chemoselective manner in the presence of Ni(cod)2, DBU, and CO2 to give the carboxylated products in good yields. The reaction was carried out under very mild conditions (CO2 1 atm, 0°C) in the presence of a stoichiometric amount of alkynes, conjugated enynes, or diynes. The high selectivity observed in the reaction would be explained in terms of the stability and the reactivity of the intermediates.
Total synthesis of (+)-himbacine and (+)-himbeline
Chackalamannil, Samuel,Davies, Robert J.,Wang, Yuguang,Asberom, Theodros,Doller, Dario,Wong, Jesse,Leone, Daria,McPhail, Andrew T.
, p. 1932 - 1940 (2007/10/03)
Himbacine (1), a complex piperidine alkaloid isolated from the bark of Australian magnolias, is a promising lead in Alzheimer's disease research due to its potent muscarinic receptor antagonist property. We have described here a highly efficient synthetic strategy that resulted in the total synthesis of himbacine (1) in about 10% overall yield and isohimbacine (1a), an unnatural isomer of himbacine, in 18% overall yield. The total synthesis of himbacine was initially approached using an intramolecular Diels-Alder reaction as the key step to generate intermediate 5 followed by a [3 + 2] cycloaddition with nitrone 4 to produce the isoxazolidine derivative 3. Methylation followed by catalytic reduction of 3 gave 12'-hydroxyhimbacine (20), which, upon dehydration, gave isohimbacine (1a) as the sole product. In an alternative approach, an all-encompassing intramolecular Diels-Alder reaction of an appropriately substituted tetraene derivative 31, which bears the entire latent carbon framework and functional group substitution of himbacine, gave the desired advanced tricyclic intermediate 33, which was readily converted to (+)-himbeline (2) and (+)-himbacine (1).
SYNTHESIS OF (E)-VINYLIC TELLURIDES AND THEIR TRANSFORMATION INTO α,β-UNSATURATED ESTERS AND CARBOXYLIC ACIDS
Dabdoub, Miguel J.,Begnini, Mauro L.,Cassol, Tania M.,Guerrero, Palimecio G.,Silveira, Claudio C.
, p. 7623 - 7626 (2007/10/02)
Zirconium alkenyls and dienyls of E configuration, obtained by the hydrozirconation of alkynes or conjugated enynes containing a terminal triple bond undergo the Zr/Te exchange reaction by treatment with C4H9TeBr or C4H9TeI in THF at -78 deg C.The Zr/Te exchange reaction proceeds with total retention of configuration and with complete stereoselectivity at the carbon 1, furnishing (E)-butyltelluro alkenes (64-86percent yields) and (E)-1-butyltelluro-1,3-dienes (68-75percent yields).Vinylic tellurides were transformed into α,β-unsaturated esters and carboxylic acids with total retention of the regio- and stereochemistry via vinyl lithium intermediates.
Synthesis of Dienoic Acids and Esters by Cationic Palladium Complex Catalyzed Carbonylation of Alkynols and Alkynediols
Huh, Keun-Tae,Orita, Akihiro,Alper, Howard
, p. 6956 - 6957 (2007/10/02)
The cationic palladium(II) aquo hydride, trans-(Cy3P)2Pd(H)(H2O)(+)BF4(-), is an excellent catalyst for the carbonylation of alkynols to dienoic acids and esters and of alkynediols to cross-conjugated diesters.
New C-C bond formation through the nickel-catalysed electrochemical coupling of 1,3-enynes and carbon dioxide
Derien, Sylvie,Clinet, Jean-Claude,Dunach, Elisabet,Perichon, Jacques
, p. 213 - 224 (2007/10/02)
A series of 1,3-enynes has been carboxylated in a nickel-catalysed electrochemical reaction carried out in a single-compartment cell fitted with a consumable magnesium anode.When 2,2'-bipyridine (bipy) or pentamethyldiethylene triamine (PMDTA) are added a
Preparation of Methine Homologues of Aldehydes and Carboxylic Acids
Zimmermann, Birgit,Lerche, Holger,Severin, Theodor
, p. 2848 - 2858 (2007/10/02)
Dilithium salts of carboxylic acids add to glyoxal mono(dimethylhydrazone) (5) to give salts of β-hydroxy carboxylic acids.Reaction with tosyl chloride affords via decarboxylation the corresponding unsaturated aldehyde hydrazones 10 or 15, which are easily hydrolyzed and oxidized to form unsaturated carboxylic acids.By this method aldehydes and/or carboxylic acids may be extended by one methine group.Extension by three methine groups can be achieved with vinylogous monohydrazones such as 23.
VINYL COPPER REAGENTS-16. SYNTHESIS OF CONJUGATED DIENES VIA THE ADDITION OF VINYL CUPRATES TO ACETYLENE
Alexakis, A.,Normant, J. F.
, p. 5151 - 5154 (2007/10/02)
Some alkenyl cuprates add smoothly to acetylene yielding dienyl cuprates.
