A novel and efficient method is proposed to evaluate the concentration polarization (CP) effect in pervaporation process. The novelty of the method results from the approach towards the CP phenomenon, that proposes the calculation algorithm on the basis of permeate fluxes and feed/permeate compo...

The formation of the macrocyclic core of crassin acetate from an acyclic precursor could be effected by ring-closing alkyne metathesis reactions while ring-closing olefin metathesis reactions failed. Installment of necessary stereochemistry was achieved by Sharpless asymmetric epoxidations on al...

In this work, we report the study of properties of capillary columns with a porous layer of the functionalized polymer prepared via oxidation of poly-(1-trimethylsilyl-1-propyne) (PTMSP) by nitrous oxide. It was shown that the double CC bonds of polymer reacted with nitrous oxide with formation ...

Palladium catalyzed asymmetric allylic alkylations of a bis(trimethylsilyl) substituted propenyl acetate and carbonate were investigated using various chiral ligands and reaction conditions. The best enantioselectivity (86% e.e.) was obtained with the substrate 1-phenyl-3,3-bis(trimethylsilyl)pr...

The kinetic and dynamic kinetic resolution of alkyl aryl carbinols carrying a trimethylsilyl group with a highly active lipase preparation containing lipoprotein lipase, dextrin, and ionic surfactant 1 has been explored. It was found that all the trimethylsilyl-containing substrates were accepte...

The interactions of 3-chloro-1-phenyl-propanol with a quinidine carbamate-bonded chiral stationary phase under NPLC conditions were studied by measuring the adsorption isotherm data of its enantiomers by frontal analysis, modeling these data with a suitable isotherm model, and comparing the expe...

A new protocol for the synthesis of 2-allylindole and 2-allylbenzofuran derivatives has been developed from readily accessible starting material, 2-((trimethylsilyl)ethynyl)arenes via Pd-catalysis. The presence of trimethylsilyl group in the alkyne is vital for this reaction. Stereoselectivity o...

The sequential synthesis of eleven novel 1-trimethysilyl-2-arylcyclohexenes 4a–k from 1-bromo-2-chlorocyclohexene (1) is reported. The Suzuki cross coupling of 1 with eleven aryl boronic acids 2a–k gave the 1-chloro-2-arylcyclohexenes 3a–k in >90% yields. Wurtz–Fittig coupling reaction of 3a...

(Trimethylsilyl)acetonitrile reacts smoothly with dimethyl acetals in the presence of stoichiometric trimethylsilyl trifluoromethanesulfonate (TMSOTf) to yield β-methoxynitriles. The ideal substrates for this reaction are acetals derived from aromatic aldehydes. Elimination to the corresponding...

A practical, operationally simple preparation of 2-(trimethylsilyl)methyl-2-propen-1-ol derivatives is described. The cobalt catalyzed coupling of a protected vinyl halide with trimethylsilylmethylmagnesium chloride shows excellent functional group tolerance and provides these synthetically usef...

N-[(2-(Trimethylsilyl)oxy)phenyl]-4-methylbenzenesulfonamide and N-[(2-trimethylsilyloxy)phenyl]-4-chlorobenzenesulfonamide were prepared by two different methods. Their structures were studied by X-ray single-crystal analysis and DFT calculations including MO and NBO analyses. Self-association ...

The 3-formate (II), 3-acetate (III), 3-bromoacetate (IV), 3-propionate (V), 3-methyl ether (VI), and 3-deoxy-derivative (VII) of 3β-hydroxyandrost-4-ene-6,17-dione (I) were synthesized and tested in human placental microsomes for their ability to inhibit aromatase. II, III, and VII of this seri...

A soluble enzyme which catalyzes the transamination of 3,5-dinitrotyrosine has been purified 300-fold from rabbit liver. Triiodothyronine, thyroxine and iodinated tyrosines were also found to serve as substrates. The activities for transamination of dinitrotyrosine and triiodothyronine migrated ...

Modified thymidine analogues have been highlighted as useful agents for the treatment of cancer and viral diseases due to their potent biological activities. In the present study, we synthesized a new thymidine analogue, 7-(3-bromo-phenoxy)-thymidine (4a), as a potential lead for anti-tumor agen...

The small chemical compound 8-ethoxy-2-(4-fluorophenyl)-3-nitro-2H-chromene (S14161) was recently identified as an inhibitor of the phosphoinositide 3-kinase (PI3K). In the present study, we designed a novel synthesis of S14161 and prepared a series of its analogues via the oxa-Michael–Henry re...

Interaction of 4-methoxy-1-naphthol (1) with α-cyano-p-chlorocinnamonitrile (2a) and ethyl α-cyano-p-chlorocinnamate (2b) provided 2-amino-4-(4-chlorophenyl)-6-methoxy-4H-benzo[h]chromene-3-carbonitrile (3a) and ethyl 2-amino-4-(4-chlorophenyl)-6-methoxy-4H-benzo[h]chromene-3-carboxylate (3b),...

A series of chroman derivatives previously reported as potassium channel openers, as well as some newly synthesized simplified structures, were examined for their in vitro effects on the growth of three human high-grade glioma cell lines: U373, T98G, and Hs683. Significant in vitro growth inhibi...

The reaction of electron deficient pyrroles and pyrazoles with trans-3-bromo-6-cyano-3,4-dihydro-2,2-dimethyl-2H-1-benzopyran-4-ol under basic conditions results in the formation of 2-isopropylbenzofurans by a mechanism which appears to be dependent on the rate of the competitive dehydration rea...

5-, 6-, 7-, and 8-Chloro-2,2-dimethylchromins have been prepared from the corresponding chloro-coumarin and their conversion into the 3,4-dihalogenochroman derivatives is described. The 4-halogen atom is shown to be the more susceptible to hydrolysis by conversion of the resulting halohydrins in...

A new practical and stereoselective method for the synthesis of the model insect antifeedant CDE fragment of azadiradione and epoxyazadiradione, based on intramolecular insertion of α-aryl-α-diazoketones, has been developed. The procedure can be applied to complex systems. A short SAR study is...