نتایج جستجو برای: oxidative aromatization
تعداد نتایج: 128973 فیلتر نتایج به سال:
A de novo palladium carbon-catalyzed synthesis of trisubstituted nicotinonitriles from easily synthesized homopropagylic or homoallylic aromatic alcohols in the presence of nitriles has been explored. The mechanism proceeds with an interesting generation of a Pd(II)-C palladacycle followed by an oxidative aromatization to generate the pyridine core. The pyridine core is generated with a notewor...
Aromatization of testosterone in Leydig cells purified from mature rat testes was assessed. Leydig cells incubated for 4 hr with increasing concentrations of [3H]testosterone. At saturating concentrations of testosterone, human chorionic gonadotropin (hCG) acutely stimulated aromatization. This stimulation was first observed at 1 hr, an 8-fold increase being found during a 4-hr incubation. The ...
The significance of in vitro aromatization of [7 alpha-3H]testosterone to estradiol by human breast cancer has been investigated by correlation with (a) estrogen receptor activity and (b) clinical response to endocrine therapy. Evidence for estradiol synthesis was obtained in 66 and estrogen receptor activity in 81 of 110 tumors. Whereas most estrogen receptor-positive tumors synthesized estrad...
The rapid and sensitive assay of lfl,2@3H-androgen aromatization by measurement of ‘HZ0 release (Thompson, E. A., Jr., and Siiteri, P. K. (1974) J. Biol. Chem. 249,5364-5372) has been analyzed to determine its applicability to initial rate studies. It was found that aromatization is the sole reaction catalyzed by lyophilized placental microsomes that causes a loss of tritium from position 1 or ...
Central (central nervous system and pituitary) aromatization appears to be a fundamental process for endocrine control and development. Metabolism of androgens to estrogens and the subsequent metabolism of estrogens have been proven in many species, including humans, and linked to estrogen action. Thus, aromatization appears to initiate or to be involved in activities of importance to endocrine...
Stereospecific nucleophilic substitution at the C-4α position of 2α-chloro-2'(2',6')-(di)halogenopicropodophyllotoxin derivatives with carboxylic acids mediated by BF3·Et2O was described. Interestingly, this stereoselective products were completely controlled by the reaction time. That is, if the reaction time was prolonged to 24.5-31 h, the resulting compounds were all transformed into the unu...
Pyrazoles and isoxazoles are well-known important heterocyclic compounds that due to their participation in the structure of many drugs are very important. Pyrazoles and isoxzaloes can be prepared by oxidation of pyrazolines and isoxazolines respectively. In this work, trans-3,5-dihydroperoxy-3,5-dimethyl-1,2-dioxalane (DHPDMDO)/NH4I has been used as a new, powerful, nearly green, effective and...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید