Oxazine containing molybdenum(VI)-oxodiperoxo complex immobilized on SBA-15 as highly active and selective catalyst in the oxidation of alkenes to epoxides under solvent-free conditions

Zare, Maryam
Moradi-Shoeili, Zeinab
Esmailpour, Parvin
Özkar, Saim
Molybdenum(VI) oxodiperoxo complex containing an oxazine ligand, ([MoO(O-2)(2)(phox)], phox: 2-(2'-hydroxyphenyl)-5,6-dihydro-1,3-oxazine) was conveniently synthesized and immobilized onto chloro-functionalized mesoporous silica SBA-15 by covalent bonding between the chloropropyl group on the internal surface of the pores and the nitrogen atom of oxazine ligand yielding [MoO(O-2)(2)(phox)]/SBA-15. The resulting material was characterized by FT-IR, TGA, XRD, SEM, TEM, EDX, ICP-AES, BET and UV-vis spectroscopy. The heterogeneous catalyst [MoO(O-2)(2)(phox)]/SBA-15 was employed in the epoxidation of alkenes, exhibiting high catalytic performance and selectivity for epoxide similar to that of homogeneous catalyst, [MoO(O-2)(2)(Phox)] under solvent-free conditions. Finally, it was found that the heterogeneous catalyst had virtually no degree of leaching, which allowed its recyclability to nine cycles without loss of catalytic performance.


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Benzaldehyde lyase from the Pseudomonas fluorescens catalyzes the reaction of aromatic aldehydes with methoxy and dimethoxy acetaldehyde and furnishes (R)-2-hydroxy-3-methoxy-1-arylpropan-1-one and (R)-2-hydroxy-3,3-dimethoxy-1-arylpropan-1-one in high yields and enantiomeric excess via acyloin linkage. Aromatic aldehydes and benzoins are converted into enamine-carbanion-like intermediates prior to carboligation.
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Araz, Mihrimah; Doğan, Özdemir; Department of Chemistry (2019)
Asymmetric 1,3-Dipolar Cycloaddition (DC) reactions of azomethine ylides are important for the synthesis of pyrrolidines. These reactions may give enantiomerically pure compounds in the presence of a chiral catalyst in a single step. Therefore, many groups have studied this reaction to synthesize aryl-substituted pyrrolidines in enantiomerically rich form. Although the aryl-substituted pyrrolidine synthesis is very common, the studies involving the heteroaryl-substituted pyrrolidines are quite rare. In gene...
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Polat-Cakir, Sidika; Demir, Ayhan Sıtkı (Elsevier BV, 2011-04-01)
We have prepared glycosyl type phosphonates via hetero Diels-Alder (HDA) reactions of acyl phosphonates with electron rich dienes. HDA reactions of acyl phosphonates with Danishefsky's diene required thermal activation to yield the desired dihydropyranones in good yield (70-91%). The reactions with Brassard's diene involved Lewis acid promotion to yield the corresponding lactones, though in moderate yield (33-69%).
BULUTAY, C; PRASAD, S (1993-06-01)
Three-dimensional condensed asymmetrical node, variable grid, transmission-line matrix (TLM) method has been used in analyzing several millimeter waveguides on anisotropic substrates. The dispersion characteristics of image guides together with field and energy confinement properties at millimeter-wave frequencies have been investigated. Edge coupled microstrip line on a uniaxial substrate is analyzed for the even and odd mode dispersion characteristics. Finally the same analysis is repeated for bilateral f...
Enantioselective Friedel-Crafts alkylation of indole with nitroalkenes in the presence of bifunctional squaramide organocatalysts
Dündar, Esra; Tanyeli, Cihangir (2021-01-01)
A series of chiral bifunctional quinine and 2-aminoDMAP based squaramide organocatalysts are evaluated in Friedel-Crafts alkylation of indoles with nitroolefins. These 3-substituted indole derivatives are synthesized in the presence of sterically encumbered tert-butyl squaramide/quinine with high enantioselectivity (up to >99% ee) and moderate chemical yields (up to 80%) by representing as chiral precursors for very important biologically active molecules. Besides, this asymmetric transformation provides a ...
Citation Formats
M. Zare, Z. Moradi-Shoeili, P. Esmailpour, S. AKBAYRAK, and S. Özkar, “Oxazine containing molybdenum(VI)-oxodiperoxo complex immobilized on SBA-15 as highly active and selective catalyst in the oxidation of alkenes to epoxides under solvent-free conditions,” MICROPOROUS AND MESOPOROUS MATERIALS, pp. 173–180, 2017, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/37395.