Synthesis and Evaluation of Estrogen Agonism of Diaryl 4,5-Dihydroisoxazoles, 3-Hydroxyketones, 3-Methoxyketones, and 1,3-Diketones: A Compound Set Forming a 4D Molecular Library
摘要:
In this paper, the preparation and systematic evaluation of estrogen receptor alpha (ER alpha) and estrogen receptor beta (ER beta) activities of some diaryl-1,3-diones and their synthetic intermediates, diaryl-4,5-dihydroisoxazoles, diaryl-3-hydroxyketones, diaryl-3-methoxyketones, and diaryl-2-(dimethyl-lambda(4)-sulfanylidene)-1,3-diones, is described. The set of 72 compounds constitutes a general schematic structure aryl1-linker1-spacer-linker2-aryl2, where the linker1-spacer-linker2 length varies between 4 and 8 carbons. The set of compounds was applied here to map and explore the active sites of subtypes ER alpha and ER beta. The highest activities were obtained with dihydroisoxazole and hydroxyketone spacers, but even the most flexible diones with unsubstituted aryl groups showed some agonism. Most compounds were found to be ER alpha selective or to activate both receptors, but in some cases we saw also clearly stronger ER beta activation.
A Convenient Preparative Method of Nitrile Oxides by the Dehydration of Primary Nitro Compounds with Ethyl Chloroformate or Benzenesulfonyl Chloride in the Presence of Triethylamine
nitrile oxides (MeOCOC≡N→O, PhC≡N→O, and EtC≡N→O) were effectively generated in situ by dehydration of the corresponding primary nitro compounds (RCH2NO2) with PhSO2Cl or ClCOOEt in the presence of triethylamine. Various cycloadducts were prepared by the reaction of them with dipolarophiles. Some advantages of these methods are described in comparison with other known methods.
O-Ethoxycarbonyl hydroximoyl chloride serves as a stable precursor for nitrileoxide and is converted into the 1,3-dipole when heated under reflux in pyridine.
were obtained from the reaction of primary nitro compounds [methyl nitroacetate, 2-nitro-1-phenylethanone, (nitromethyl)benzene, 1-nitropropane, and (phenylsulfonyl)nitromethane] with dipolarophiles in refluxing mesitylene in the presence of a small amount of p-toluenesulfonic acid. The formation of these products can be explained in terms of 1,3-dipolar cycloaddition of nitrileoxide generated by a
One-Pot Synthesis of Isoxazolines from Aldehydes Catalyzed by Iodobenzene
作者:Jie Yan、Liuquan Han、Bijun Zhang、Changbin Xiang
DOI:10.1055/s-0033-1340464
日期:——
finally, a 1,3-dipolarcycloaddition between the nitrileoxides and alkenes occurs to provide the isoxazolines in moderate to good yields. A convenient one-pot, three-step procedure for the synthesis of isoxazolines starting from aldehydes has been developed involving catalytic cycloaddition between nitrileoxides and alkenes, in which iodobenzene is used as the catalyst for the in situgeneration of a hypervalent
Hypervalent Iodine–Catalyzed Cycloaddition of Nitrile Oxides to Alkenes
作者:Changbin Xiang、Tingting Li、Jie Yan
DOI:10.1080/00397911.2013.834364
日期:2014.3.4
convenient method for preparation of isoxazolines was developed by a catalytic cycloaddition of nitrileoxides generated in situfrom aldoximes to alkenes in the presence of a catalytic amount of iodobenzene. In this protocol, iodobenzene was first oxidized into the hypervalent iodine intermediate by m-chloroperbenzoic acid, which then transformed aldoximes into nitrileoxides, and a 1,3-dipolar cycloaddition