Quinolones as gonadotropin releasing hormone (GnRH) antagonists: simultaneous optimization of the C(3)-aryl and C(6)-substituents
摘要:
A series of 3-arylquinolones was prepared and evaluated for their ability to act as gonadotropin releasing hormone (GnRH) antagonists. A variety of substitution patterns of the 3-aryl substituent are described. The 3,4,5-trimethylphenyl substituent (23h) was found to he optimal. (C) 2000 Elsevier Science Ltd. All rights reserved.
The BF3-catalyzed decomposition of m- and p-substituted α-diazoacetophenones in excess of methyl thiocyanate and ethyl thiocyanate gave the corresponding 2-methylthio-, and 2-ethylthio-5-aryloxazoles, respectively in good yields along with s-alkyl-n-aroylmethylthiocarbamates and α-ethoxyacetophenones. However, yields of 2-dimethylamino-5-aryloxazoles by the reaction of dimethylcyanamide with α-diazoacetophenones
Origin of the Relative Stereoselectivity of the β-Lactam Formation in the Staudinger Reaction
作者:Lei Jiao、Yong Liang、Jiaxi Xu
DOI:10.1021/ja056711k
日期:2006.5.1
stereoselectivity of the beta-lactam formation is one of the critical issues in the Staudinger reaction. Although many attempts have been made to explain and to predict the stereochemical outcomes, the origin of the stereoselectivity remains obscure. We are proposing a model that explains the relative stereoselectivity based on a kinetic analysis of the cis/trans ratios of reaction products. The results were
Formation of Acyl-Substituted Nitrile Ylides by Rh<sub>2</sub>(OAc)<sub>4</sub>-Catalyzed Decomposition of<i>α</i>-Diazocarbonyl Compounds in Nitriles
作者:Kazuaki Fukushima、Toshikazu Ibata
DOI:10.1246/bcsj.68.3469
日期:1995.12
The Rh2(OAc)4-catalyzed reactions of α-diazocarbonyl compounds in nitrile in the presence of dimethyl acetylenedicarboxylate (DMAD) gave oxazole and pyrrole derivatives. The formation of the oxazole derivatives is explained in terms of the 1,5-cyclization of an acyl-substituted nitrileylide intermediate, and the formation of the pyrrole derivatives is explained by the 1,3-dipolar cycloaddition of
Formation and Reaction of Acyl Substituted Nitrile Ylide through the Rh<sub>2</sub>(OAc)<sub>4</sub>-Catalyzed Reaction of α-Diazocarbonyl Compounds with Benzonitrile
作者:Toshikazu Ibata、Kazuaki Fukushima
DOI:10.1246/cl.1992.2197
日期:1992.11
The rhodium(II) acetate-catalyzedreaction of α-diazocarbonyl compounds with benzonitrile and dimethyl acetylenedicarboxylate gave oxazoles and pyrrole-3,4-dicarboxylates through the 1,5-cyclizatio...
A simple and efficient method to obtain α-xanthylmethyl ketones from α-diazo ketones is described. The reaction proceeds through a protonation/nucleophilic substitution sequence in the presence of p-toluenesulfonic acid and potassium ethyl xanthogenate as the nucleophile. As α-diazo ketones can be readily synthesized from ubiquitous carboxylic acids, a broad variety of xanthates can be obtained, including