نتایج جستجو برای: phosphorus ylide
تعداد نتایج: 41924 فیلتر نتایج به سال:
سنتز ایلیدهای فسفر یکی از واکنشهای مهم شیمی آلی است زیرا این ترکیبات کاربرد زیادی در سنتز مواد آلی دارند.
Practical stereoselective synthetic routes to the antihistaminic drug olopatadine and its E-isomer have been developed, the key steps being a trans stereoselective Wittig olefination using a nonstabilized phosphorus ylide and a stereoselective Heck cyclization. The stereoselectivity of the Wittig reaction depends on both the phosphonium salt anion and the cation present in the base used to gene...
The unsymmetrical phosphorus ylide, Ph2PCH2CH2PPh2@C(H)C(O)Ph is shown to react with Hg(II) halides to form polymeric products with the composition {HgX2[PPh2CH2CH2PPh2C(H)C(O)Ph]}n, where X = Cl (1), Br (2), I (3). The complexes have been characterized by elemental analysis, IR, H, P NMR spectra as well as by ESI mass spectra. In product 1 the ylide exhibits a P, C-bridging mode of coordinatio...
Cross-conjugated bifunctional species including a phosphine, phosphine oxide, phosphine sulfide, phosphonium salt, phosphorus ylide and a gold(I) phosphine complex have been prepared. The photophysical characteristics of the series of compounds have been determined experimentally and are discussed/compared with simpler analogues lacking cross-conjugated branches and rationalized on the basis of...
In this paper, the chemical Functionalization of Carboxylate multi-walled carbon nanotubes by methyl (triphenyl phosphoranylidene) acetate have been investigated. Phosphorus Ylides are important compound in organic chemistry. At first, methyl (triphenyl phosphoranylidene) acetate, synthesized from salt metod in two steps: the formation of the phosphonium salt and the deprotonation of the latter...
in this paper, the chemical functionalization of carboxylate multi-walled carbon nanotubes by methyl (triphenyl phosphoranylidene) acetate have been investigated. phosphorus ylides are important compound in organic chemistry. at first, methyl (triphenyl phosphoranylidene) acetate, synthesized from salt metod in two steps: the formation of the phosphonium salt and the deprotonation of the latter...
In this paper, the chemical Functionalization of Carboxylate multi-walled carbon nanotubes by methyl (triphenyl phosphoranylidene) acetate have been investigated. Phosphorus Ylides are important compound in organic chemistry. At first, methyl (triphenyl phosphoranylidene) acetate, synthesized from salt metod in two steps: the formation of the phosphonium salt and the deprotonation of the latter...
Pseudo-C2-symmetric chiral phosphorus ylides have been designed and synthesized for the enantioselective preparation of allenic esters, and up to 92% ee has been achieved.
Ab initio calculations are presented for several species containing a silicon-phosphorus bond. The types of bonding studied include "normal" single, double, and triple bonds, as well as an ylide-like structure. The latter is found to be much less strongly bound than the carbon analogue, with a smaller stretching force constant than that in silylphosphine. The insertions of silylene into the pho...
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