نتایج جستجو برای: vsba 16 catalyst
تعداد نتایج: 376679 فیلتر نتایج به سال:
Triethylborane (TEB) was found to be a mild, efficient, and acid catalyst in electrophilic substitution reaction of indoles with aldehydes compounds to afford the corresponding bis(indolyl)methanes. Vibrindole A (5) and bis(indolyl)methanes derivatives 16 and 18 were synthesized using this methodology. Compound 16 is an intermediary in the synthesis of the natural bisindoles arsindoline B (2) a...
Herein, we prepared a V/SBA-16 catalyst using vanadyl acetylacetonate as a precursor and SBA-16 nanoporous silica as a support via an immobilization technique. The ordered mesoporous structure of catalyst was determined by X-ray diffraction and transmission electron microscopy techniques , and the catalyst was evaluated in the benzene hydroxylation to phenol with hydrogen peroxide (H2O2) as a ...
This paper argues that innovation can be best understood as an information process which is then concretized as a product that meets demand. Two very different firms, Canon Inc. and Apple Computer Inc., are used as case study illustrations. Innovation does not proceed through logical deduction, but rather is furthered by the use of metaphors and analogies. The bureaucratic and staid structures ...
The observation of Manchot? that sodium pentacyano-ammineferroate2 I absorbs oxygen has led Baudisch and his coworkers3 to study the catalytic action of this salt, as well as of its water analogue II, in the oxidation of pyrimidines and purines. The present authors have previously reported in this journal4 on the nature of the oxidation products obtained. In the present paper the problem is con...
Efficient regioselective synthesis of nucleoside conjugates was achieved by cycloaddition reaction of azides and alkynes using sodium ascorbate/ CuSO4 system as a catalyst. These 16 novel thymidine analogues were obtained in excellent yields (75-100%), employing mild reaction conditions with a broad scope of structural modification. For the compounds tested, no specific antiviral effects could ...
The highly chemo-, regio-, and stereoselective synthesis of alkyl- and vinyl boronic esters with good functional group tolerance has been developed using in situ activation of a bench-stable iron(II) pre-catalyst and pinacolborane (16 examples, 45-95% yield, TOF up to 30,000 mol h(-1)). The first iron-catalysed alkene hydrogermylation is also reported.
Aromatic aldehydes and ketones as well as aromatic epoxides are selectively reduced to the corresponding alcohols under mild conditions using conventional hydrogen in the presence of Pd(0)EnCat 30NP catalyst. The reactions were performed at room temperature during 16 hours with high to excellent conversions of the corresponding products.
The air stable asarone-derived Ru carbene 16, a robust olefin metathesis catalyst, can be easily separated after reaction by deposition on silica gel and reused up to nine times. This procedure provides products of excellent purity with low Ru content.
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