81631-63-2Relevant academic research and scientific papers
Photocatalytic transfer hydrogenolysis of aromatic ketones using alcohols
Gao, Zhuyan,Han, Jianyu,Hong, Feng,Lei, Lijun,Li, Hongji,Liu, Huifang,Luo, Nengchao,Wang, Feng
, p. 3802 - 3808 (2020/07/09)
A mild method of photocatalytic deoxygenation of aromatic ketones to alkyl arenes was developed, which utilized alcohols as green hydrogen donors. No hydrogen evolution during this transformation suggested a mechanism of direct hydrogen transfer from alcohols. Control experiments with additives indicated the role of acid in transfer hydrogenolysis, and catalyst characterization confirmed a larger number of Lewis acidic sites on the optimal Pd/TiO2 photocatalyst. Hence, a combination of hydrogen transfer sites and acidic sites may be responsible for efficient deoxygenation without additives. The photocatalyst showed reusability and achieved selective reduction in a variety of aromatic ketones.
New Fluorescence Domain "excited Multimer" Formed upon Photoexcitation of Continuously Stacked Diaroylmethanatoboron Difluoride Molecules with Fused π-Orbitals in Crystals
Sakai, Atsushi,Ohta, Eisuke,Yoshimoto, Yuichi,Tanaka, Mirai,Matsui, Yasunori,Mizuno, Kazuhiko,Ikeda, Hiroshi
supporting information, p. 18128 - 18137 (2015/12/24)
The crystal-packing structures of seven derivatives of diaroylmethanatoboron difluoride (1 a-gBF2) are characterized by no overlap of the π-conjugated main units of two adjacent molecules (typeI), overlap of the benzene ring π-orbitals of two adjacent molecules (typeII), and overlap of the benzene and dihydrodioxaborinine rings π-orbitals of adjacent molecules (typeIII). The crystal-packing structures govern the fluorescence (FL) properties in the crystalline states. The FL domain that is present in typeI crystals, in which intermolecular orbital interactions are absent, leads to excited monomer-like FL properties. In the case of the typeII crystals, the presence of intermolecular overlap of the benzene rings π-orbitals generates new FL domains, referred to as "excited multimers", which possess allowed S0-S1 electronic transitions and, as a result, similar FL lifetimes at longer wavelengths than the FL of the typeI crystals. Finally, intermolecular overlap of the benzene and dihydrodioxaborinine ring π-orbitals in the typeIII crystals leads to "excited multimer" domains with forbidden S0-S1 electronic transitions and longer FL lifetimes at similar wavelengths as that in typeI crystals.
Unusual orthogonality in the cleavage process of closely related chelating protecting groups for carboxylic acids by using different metal ions
Mundinger, Stephan,Jakob, Uwe,Bannwarth, Willi
supporting information, p. 1258 - 1262 (2014/04/03)
Three structurally related relay protecting groups for carboxylic acids that are based on chelating amines have been developed. These protecting groups can easily be introduced by coupling the carboxylic acid and the corresponding amine in the presence of 2-(1Hbenzotriazole-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate (TBTU). In addition to being stable to a whole array of reaction conditions, these protecting groups are also stable under acidic and basic conditions, allowing them to be used in combination with the ester protection of carboxylic acids. The cleavage of these protecting groups is activated by the chelation of metal ions, involving an unusual coordination of the amide nitrogen. Despite their similarity, cleavage of these protecting groups is possible in both a stepwise and an orthogonal fashion by applying different metal salts.
Synthesis and evaluation of some substituted heterocyclic fluconazole analogues as antifungal agents
Wang, Shudong,Zhang, Lei,Jin, Yongsheng,Tang, Jin Hao,Su, Hua,Yu, Shichong,Ren, Haixiang
, p. 2362 - 2364 (2014/06/09)
A new series of fluconazole analogues of 1-(1H-1,2,4-triazol-1-yl)-2-(2,4- difluoro-phenyl)-3-4-(substituted-heterocyclic ring-1H-1,2,3- triazol-1-yl)-2-propanols (1-10) were designed, synthesized and evaluated as antifungal agents. Preliminary antifungal tests showed that most of the title compounds exhibited moderate activity with broad spectrum against eight human pathogenic fungi in vitro, compounds 1 and 6 had the best antifungal activity against Candida albicans with the value of MIC80 = 0.5 μg/mL respectively.
PIFA-mediated esterification reaction of alkynes with alcohols via oxidative cleavage of carbon triple bonds
Jiang, Qing,Zhao, An,Xu, Bin,Jia, Jing,Liu, Xin,Guo, Cancheng
, p. 2709 - 2715 (2014/04/17)
A metal-free esterification of alkynes via C≡C triple bond cleavage has been developed. In the presence of phenyliodine bis(trifluoroacetate), a diverse range of alkyne and alcohol substrates undergoes triple bond cleavage to produce carboxylic ester motifs in moderate to good yields. The transformation is proposed to proceed via hydroxyethanones and ethanediones as intermediates on the basis of mechanistic studies and exhibits a broad substrate scope and good functional group tolerance.
N-Tosylhydrazine-mediated deoxygenative hydrogenation of aldehydes and ketones catalyzed by Pd/C
Zhou, Lei,Liu, Zhenxing,Liu, Yizhou,Zhang, Yan,Wang, Jianbo
, p. 6083 - 6087 (2013/07/25)
A mild and efficient method for the deoxygenative hydrogenation of aldehydes and ketones has been developed. The reaction is mediated by N-tosylhydrazine with H2 (1 atm) as the reductant and 10% Pd/C as the catalyst.
Pd-PEPPSI-IPentCl: A highly effective catalyst for the selective cross-coupling of secondary organozinc reagents
Pompeo, Matthew,Hadei, Niloufar,Organ, Michael G.,Froese, Robert D. J.
supporting information, p. 11354 - 11357,4 (2012/12/12)
No migration? No problem. A series of new N-heterocyclic carbene based Pd complexes has been created and evaluated in the Negishi cross-coupling of aryl and heteroaryl chlorides, bromides, and triflates with a variety of secondary alkylzinc reagents (see scheme). The direct elimination product is nearly exclusively formed; in most examples there is no migratory insertion at all. Copyright
Pd-PEPPSI-IPentCl: A highly effective catalyst for the selective cross-coupling of secondary organozinc reagents
Pompeo, Matthew,Froese, Robert D. J.,Hadei, Niloufar,Organ, Michael G.
supporting information, p. 11354 - 11357 (2013/01/15)
No migration? No problem! A series of new N-heterocyclic carbene based Pd complexes has been created and evaluated in the Negishi cross-coupling of aryl and heteroaryl chlorides, bromides, and triflates with a variety of secondary alkylzinc reagents (see scheme). The direct elimination product is nearly exclusively formed; in most examples there is no migratory insertion at all. Copyright
Nickel-catalyzed Negishi cross-coupling reactions of secondary alkylzinc halides and aryl iodides
Joshi-Pangu, Amruta,Ganesh, Madhu,Biscoe, Mark R.
supporting information; experimental part, p. 1218 - 1221 (2011/04/27)
A general Ni-catalyzed process for the cross-coupling of secondary alkylzinc halides and aryl/heteroaryl iodides has been developed. This is the first process to overcome the isomerization and β-hydride elimination problems that are associated with the use of secondary nucleophiles, and that have limited the analogous Pd-catalyzed systems. The impact of salt additives was also investigated. It was found that the presence of LiBF4 dramatically improves both isomeric retention and yield for challenging substrates.(Figure Presented)
Negishi cross-coupling of secondary alkylzinc halides with aryl/heteroaryl halides using Pd-PEPPSI-IPent
Alimsiz, Seluk,Organ, Michael G.
supporting information; experimental part, p. 5181 - 5183 (2011/06/09)
Pd-PEPPSI-IPent has proven to be an excellent catalyst for the Negishi cross-coupling reaction of secondary alkylzinc reagents with a wide variety of aryl/heteroaryl halides. Importantly, β-hydride elimination/migratory insertion of the organometallic leading to the production of isomeric coupling products has been significantly reduced using the highly-hindered Ipent ligand.
