We have developed a new method of iodocyclization based on reagent-controlled oxidative aromatization. Our strategy takes advantage of the dual nature of iodine as both an iodinating and an oxidizing agent. This approach enabled "product switch" and enhanced the flexibility of the synthetic pathway toward pyrazoles and isoxazoles. In addition, the iodo moiety of the cyclized product could creat...

Molecular oxygen can replace sacrificial olefins as the hydrogen acceptor in the palladium trifluoroacetate catalyzed dehydrogenation of cyclohexene and related cyclic olefins into aromatics. One of the major drawbacks of the homogeneous system is the tendency of the palladium trifluoroacetate to precipitate as palladium(0) at elevated temperatures. The use of better ligands affords catalysts t...

A 2,4-diarylquinoline derivative, 2-(4-chlorophenyl)-4-(3,4-dimethoxyphenyl)-6-methoxy-3-methylquinoline, was synthesized in a conventional two-step procedure from p-anisidine, p-chlorobenzaldehyde and methyl isoeugenol as available starting reagents through sequence of BF3·OEt2-catalyzed Povarov cycloaddition reaction/oxidative dehydrogenation aromatization processes under microwave irradiatio...

To study the effect of calcium ion on aromatization of an androgenic precursor to estradiol by the placenta, cultured term trophoblasts were used as a model system. Secretion of estradiol into the culture medium was regarded as indicating aromatization, since cells cultured with no androgenic precursors produced only insignificant amounts of estradiol. EGTA, verapamil and ionophore A23187 inhib...

The aromatization of androstenedione is inhibited in the presence of aminoglutethimide, diethylaminoethyl-2,2-diphenyl valerate HCl (SKF 525-A), and 1W3 M KCN, but not carbon monoxide or metyrapone. The role of cytochrome P-450 in this reaction could not, therefore, be unequivocally established by inhibition studies. However, it was determined that steroid binding to placental microsomal cytoch...

In this study, oxidation of some 3,5-diacyl or 3,5-diester 1,4-dihydropyridines to corresponding pyridine derivatives using sodium bromate in the presence of NH4Cl, NaHSO4 and Bu4NHSO4 under thermal conditions has been investigated. The yield and structure of formed products is similar under all conditions; however, the reaction is accelerated in the presence of Bu4NHSO4 and NaHSO4. In addition...

The aromatization reaction of liquefied petroleum gas has been studied by using three liquefied petroleum gases as raw material and LBO-A as catalyst, and four lump kinetics models networks have been put up on the basis of lump theory and the aromatization reaction mechanism. In the network the aromatization reaction species was firstly lumped into C 4 , propylene, low molecule hydrocarbon, liq...

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...

The synthesis of 3-amino-2-methoxycarbonyl-4,7-dimethoxybenzo[b]thiophene (5) and benzothieno[3,2-d][1,3]oxazin 15 from 3,6-dimethoxy-2-nitrobenzaldehyde (1) is reported. Benzo[b]thiophene-4,7-quinones 9 and 10 were prepared in good yields by oxidative deprotection of the corresponding dimethoxybenzothiophenes 8 and 7. Cycloaddition reaction of quinone 8 with 1-(E)-trimethylsilyloxy-1,3-butadie...