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.


Benzaldehyde lyase-catalyzed enantioselective carboligation of aromatic aldehydes with mono- and dimethoxy acetaldehyde
Demir, Ayhan Sıtkı; Sesenoglu, O; Dunkelmann, P; Muller, M (American Chemical Society (ACS), 2003-06-12)
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.
Enantioselective synthesis of furyl-substituted pyrrolidines
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...
Hetero Diels-Alder reactions of acyl phosphonates: synthesis of glycosyl type phosphonates
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%).
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 ...
Boron trifluoride mediated addition of nucleophiles to endo- and exo-substituted norbornene derivatives
İŞLEYEN, Alper; SAYRAÇ, Tuğmaç; Doğan, Özdemir (2004-01-01)
Remote substituent effects on the regioselectivity and stereoselectivity in the boron trifluoride mediated addition of nucleophiles (iodide and bromide) to endo- and exo-2-substituted norbornene derivatives have been investigated. The main products of the reactions resulted from the regioselective addition of nucleophiles to the double bond of norbornene derivatives. Products resulting from the Wagner-Meerwein type rearrangement were also isolated in considerable amounts. All of the reactions gave the addit...
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.