5472-01-5Relevant academic research and scientific papers
Stable and Reusable Palladium Nanoparticles-Catalyzed Conjugate Addition of Aryl Iodides to Enones: Route to Reductive Heck Products
Parveen, Naziya,Saha, Rajib,Sekar, Govindasamy
, p. 3741 - 3751 (2017/11/15)
An efficient, binaphthyl-backbone-stabilized palladium nanoparticles (Pd-BNP) catalyst for the 1,4-addition of aryl halides to enones has been developed. The scope of the reaction has been studied with various substituted and sterically hindered aryl hali
Base-Catalyzed Stereospecific Isomerization of Electron-Deficient Allylic Alcohols and Ethers through Ion-Pairing
Martinez-Erro, Samuel,Sanz-Marco, Amparo,Bermejo Gómez, Antonio,Vázquez-Romero, Ana,Ahlquist, M?rten S. G.,Martín-Matute, Belén
, p. 13408 - 13414 (2016/10/22)
A mild base-catalyzed strategy for the isomerization of allylic alcohols and allylic ethers has been developed. Experimental and computational investigations indicate that transition metal catalysts are not required when basic additives are present. As in the case of using transition metals under basic conditions, the isomerization catalyzed solely by base also follows a stereospecific pathway. The reaction is initiated by a rate-limiting deprotonation. Formation of an intimate ion pair between an allylic anion and the conjugate acid of the base results in efficient transfer of chirality. Through this mechanism, stereochemical information contained in the allylic alcohols is transferred to the ketone products. The stereospecific isomerization is also applicable for the first time to allylic ethers, yielding synthetically valuable enantioenriched (up to 97% ee) enol ethers.
Decarboxylative substitution of β-keto acids to benzylic alcohols catalyzed by molecular iodine
Han, Fuzhong,Zhang, Xinxin,Hu, Minggang,Jia, Lina
, p. 11466 - 11471 (2015/12/04)
An efficient method for molecular iodine catalyzed decarboxylative substitution of β-keto acids with benzylic alcohols under mild conditions has been described and valuable α-functionalized ketones were obtained in good to excellent yields.
Wide bite angle diphosphine rhodium complexes: Synthesis, structure, and catalytic 1,4-addition of arylboronic acids to enones
Morgan, Brad P.,Smith, Rhett C.
, p. 11 - 16 (2008/03/14)
A rhodium complex [ClRh(CO)(L1)] featuring a wide bite angle diphosphine ligand (L1 = 1,3-bis(2-diphenylphosphinomethylphenyl)benzene) has been synthesized and structurally characterized. L1 supports a bite angle (P-M-P angle, β) of 171.4° in the trans-square planar complex. L1 was tested in Rh-catalyzed 1,4-addition reactions of arylboronic acids (six examples) to α,β-unsaturated ketones (five examples). In mixed aqueous/cyclohexane solution at 60 °C, addition reactions proceed in up to quantitative yield with a 1:1 arylboronic acid/enone ratio. Yields as high as 77% can be acquired even when one of the coupling partners is sterically encumbered 2,4,6-trimethylphenylboronic acid.
Conjugate additions of α,β-unsaturated ketones with arylzinc species that form in situ from diethylzinc and arylboronic acids
Dong, Lin,Xu, Yan-Jun,Gong, Liu-Zhu,Mi, Ai-Qiao,Jiang, Yao-Zhong
, p. 1057 - 1061 (2007/10/03)
Conjugate addition of α,β-unsaturated ketones with arylzinc species that form in situ from diethylzinc and a series of arylboronic acids by boron-zinc exchange reactions were investigated. 1,4-Addition products were formed in yields of 34-93%.
Superacid-Catalyzed Reactions of Cinnamic Acids and the Role of Superelectrophiles
Rendy, Rendy,Zhang, Yun,McElrea, Aaron,Gomez, Alma,Klumpp, Douglas A.
, p. 2340 - 2347 (2007/10/03)
The chemistry of cinnamic acids and related compounds has been studied. In superacid-catalyzed reactions with arenes, two competing reaction mechanisms are proposed. Both mechanisms involve the formation of dicationic intermediates (superelectrophiles), and the reactions can lead to either chalcone-type products or indanone products. The direct observation of a dicationic species (by low-temperature 13C NMR) is reported. We provide clear evidence that protonated carboxylic acid groups (or the corresponding acyl cation) can enhance the reactivity of an adjacent electrophilic center. Triflic acid is also found to be an effective acid catalyst for the direct synthesis of some electron-deficient chalcones and heterocyclic chalcones from cinnnamic acids.
