27948-29-4Relevant academic research and scientific papers
Stoichiometric and Catalytic C?C and C?H Bond Formation with B(C6F5)3 via Cationic Intermediates
Soltani, Yashar,Wilkins, Lewis C.,Melen, Rebecca L.
, p. 11995 - 11999 (2017)
This work showcases a new catalytic cyclization reaction using a highly Lewis acidic borane with concomitant C?H or C?C bond formation. The activation of alkyne-containing substrates with B(C6F5)3 enabled the first catalytic intramolecular cyclizations of carboxylic acid substrates using this Lewis acid. In addition, intramolecular cyclizations of esters enable C?C bond formation as catalytic B(C6F5)3 can be used to effect formal 1,5-alkyl migrations from the ester functional groups to unsaturated carbon–carbon frameworks. This metal-free method was used for the catalytic formation of complex dihydropyrones and isocoumarins in very good yields under relatively mild conditions with excellent atom efficiency.
Essential structural features of (2Z,4E)-5-phenylpenta-2,4-dienoic acid for inhibition of root gravitropism
Shindo, Mitsuru,Makigawa, Saki,Matsumoto, Kenji,Iwata, Takayuki,Wasano, Naoya,Kano, Arihiro,Morita, Miyo Terao,Fujii, Yoshiharu
, (2020/02/04)
Previously, we found (2Z,4E)-5-phenylpenta-2,4-dienoic acid (ku-76) to be a selective inhibitor of root gravitropic bending of lettuce radicles at 5 μM, with no concomitant growth inhibition. Here, we describe a structure-activity relationship study of ku
Palladium-catalyzed difunctionalization of internal alkynes via highly regioselective 6- endo cyclization and alkenylation of enynoates: Synthesis of multisubstituted pyrones
Tian, Pan-Pan,Cai, Sai-Hu,Liang, Qiu-Ju,Zhou, Xing-Yi,Xu, Yun-He,Loh, Teck-Peng
, p. 1636 - 1639 (2015/04/14)
An efficient Pd(II)-catalyzed difunctionalization reaction of internal alkynes is reported. In this reaction, various enynoates and electron-deficient alkenes were used for the syntheses of useful highly substituted pyrone derivatives via a 6-endo cycliza
Catalytic and selective conversion of (Z)-2-en-4-ynoic acids to either 2H-pyran-2-ones in the presence of ZnBr2 or (Z)-5-alkylidenefuran-2(5H)-ones in the presence of Ag2CO3
Anastasia, Luigi,Xu, Caiding,Negishi, Ei-Ichi
, p. 5673 - 5676 (2007/10/03)
Treatment of (Z)-5-alkyl-2-en-4-ynoic acids (1), prepared by the Pd-catalyzed alkynylzinc-β-haloacrylic acid coupling, with 5-10 mol% of ZnBr2 can produce 6-alkyl-2H-pyran-2-ones (2) along with minor amounts of (Z)-5-alkylidenefuran-2(5H)-ones (3) in >90% combined yields, with often very high (≈95/5) pyranone/furanone ratios. On the other hand, lactonization of 1 catalyzed by Ag2CO3 provides a selective synthesis of (Z)-5-alkylidenefuran-2(5H)-ones (3) in >90% yields along with minor amounts (≤5%) of 2.
Selective synthesis of natural and unnatural 5,6-disubstituted 2(2H)-pyranones via iodolactonization of 5-substituted (Z)-2-en-4-ynoic acids
Bellina,Biagetti,Carpita,Rossi
, p. 2857 - 2870 (2007/10/03)
Reaction of 5-substituted (Z)-2-en-4-ynoic acids with iodine and NaHCO3 in CH3CN or with ICl in CH2Cl2 affords mixtures of (E)-5-(1-iodoylidene)-2(5H)-furanones and 6-substituted 5-iodo-2(2H)-pyranones in which these last compounds are the major products. The 5-iodo-2(2H)-pyranones, which are easily separated chromatographically from the corresponding regioisomers, are able to undergo Stille-type reactions with a variety of organotin compounds to give 5,6-disubstituted 2(2H)-pyranones in moderate to good yields. One of these compounds, i.e. 5-(1-butynyl)-2(2H)-pyranone, has been used as direct precursor to two substances produced by fungal culture LL-11G219, which function as androgen ligands, i.e. (Z)-5-(1-butenyl)-6-methyl-2(2H)-pyranone and 5-butyl-6-methyl-2(2H)-pyranone.
Palladium-catalyzed synthesis of stereodefined 3-[(1,1-unsymmetrically disubstituted)methylidene]isobenzofuran-1(3H)-ones and stereodefined 5-[(1,1- unsymmetrically disubstituted)methylidene]furan-2(5H)-ones
Rossi, Renzo,Bellina, Fabio,Biagetti, Matteo,Catanese, Antonella,Mannina, Luisa
, p. 5281 - 5286 (2007/10/03)
Treatment of (hetero)aryl halides with 2-(1-alkynyl)benzoic acids or (Z)-2-en-4-ynoic acids in the presence of K2CO3 and a catalytic amount of Pd(PPh3)4 provides reaction mixtures in which stereodefined 3-[(1,1-
