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191.
A facile method for the benzylic bromination of toluene derivatives was developed. Various substituted toluenes were brominated with boron tribromide as bromine source in carbon tetrachloride at room temperature, affording their corresponding benzyl bromides in good yields. 相似文献
192.
Direct synthesis of 1,1-disubstitued 1,3-butadienes has been efficiently realized from the cross-coupling of cyclopropylmethyl N-tosylhydrazones with aromatic bromides by means of PdCl2(MeCN)2 as catalyst. 1,1,4-Trisubstitued 1,3-butadiene derivatives were obtained in up to 70% yields through a one-pot procedure catalyzed by Pd(OAc)2 in the presence of excessive amount of aromatic bromides. The present methodology provides an easy and efficient route to multisubstituted 1,3-butadienes. 相似文献
193.
A novel task-specific ionic liquid, 1-butyl-3-methylimidazolium p-toluenesulfinate, [bmim][p-TolSO2] has been synthesized and used as a nucleophile for the reaction with alkyl bromides and phenacyl bromides to prepare sulfones and β-ketosulfones in excellent yields (80-93%) in [bmim][BF4] ionic liquid. The isolated yields of sulfones and β-ketosulfones were higher in [bmim][BF4] than other organic solvents at room temperature. 相似文献
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195.
An alternative method for synthesis of biaryls has been developed through the Pd catalyzed desulfitative coupling reaction of sodium arylsulfinates with aryl bromides and chlorides. The procedure tolerates a variety of functional groups, such as cyano, formyl, acetyl, chloro, methoxy, trifluoromethyl and heteroaromatic unit. The desired products were obtained in moderate to excellent yields under relatively mild reaction conditions without additives, base or co-catalyst. 相似文献
196.
Niraj K. Ladani Manish P. Patel Ranjan G. Patel 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3):658-662
A series of 3-(2-phenyl-6-(2-thienyl)-4-pyridyl)hydroquinolin-2-ones 4a–o were synthesized in high yields by a one–pot cyclocondensation reaction under Kröhnke's reaction conditions using 2-chloro-3-formyl quinoline 1a–c, 2-acetyl thiophene 2, and various N-phenacylpyridinium bromides 3a–e in a mixture of ammonium acetate and acetic acid by microwave irradiation. All the compounds have been characterized by elemental analysis, FT-IR, 1H NMR, and 13C NMR spectral analysis. These compounds have been screened for their antimicrobial activities. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. 相似文献
197.
Synthesis of α,α‐Difluoromethylene Alkynes by Palladium‐Catalyzed gem‐Difluoropropargylation of Aryl and Alkenyl Boron Reagents
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Yan‐Bo Yu Guo‐Zhen He Prof. Dr. Xingang Zhang 《Angewandte Chemie (International ed. in English)》2014,53(39):10457-10461
gem‐Difluoropropargyl bromides are versatile intermediates in organic synthesis, but have rarely been employed in transition‐metal‐catalyzed cross‐coupling reactions. The first palladium‐catalyzed gem‐difluoropropargylation of organoboron reagents with gem‐difluoropropargyl bromides is now reported. The reaction proceeds under mild reaction conditions with high regioselectivity; it features a broad substrate scope and excellent functional‐group compatibility and thus provides an attractive approach for the synthesis of complex fluorinated molecules, in particular for drug discovery and development. 相似文献
198.
199.
Shi Tang Li Yuan Zeng-Zeng Li Zhi-Yuan Peng You-Lin Deng Liang-Neng Wang Gui-Xiu Huang Rui-Long Sheng 《Tetrahedron letters》2017,58(22):2127-2130
A feasible approach to 2-azaspirocyclic cyclohexadienones via visible-light-induced perfluoroalkylation cyclization of N-benzylacrylamides was reported. Using Rf-X (X = I or Br) as the Rf radical source, the reaction underwent a cascade radical addition/dearomative cyclization process by Ir photocatalyst, leading to various 2-azaspiro[4.5]deca-6,9-diene-3,8-diones bearing perfluorinated groups including CF3, n-C3F7, n-C4F9, n-C6F13, n-C8F17, n-C10F21, CH2CF2 and CF2CO2Et. 相似文献
200.