Ruthenium nanoparticles supported on hydroxyapatite as an efficient and recyclable catalyst for cis-dihydroxylation and oxidative cleavage of alkenes

Impregnation of hydroxyapatite with colloidal ruthenium results in the formation of a catalyst that effects cis-dihydroxylation and oxidative cleavage of alkenes to their respective cis-1,2-diols and carbonyl products in good to excellent yields (see scheme). The supported ruthenium catalyst can be easily recycled and reused for consecutive reaction runs without significant deterioration of the catalytic activities. R1, R2 = H, alkyl, aryl.postprin

Ruthenium-oxo and -tosylimido porphyrin complexes for epoxidation and aziridination of alkenes

Dioxoruthenium(VI) porphyrins including those containing chiral porphyrinato ligands can be readily prepared by oxidation of [Ru 11(Por)(CO)(MeOH)] with PhIO or metachloroperoxybenzoic acid. Similar reactions with PhINTs gave [Ru VI(Por)(NTs) 2] isolated as air stable solids at room temperature. The [Ru VI(Por)O 2] complexes are competent oxidants for epoxidation of alkenes with high selectivities. Enantioselective epoxidation of alkenes giving the corresponding organic epoxides with moderate to good enantioselectivites have also been achieved using chiral [Ru VI(D 4-Por)O 2] [D 4-H 2Por= 5,10,15,20-tetrakis-(IS,4R,5R,8S-1,2,3,4,5,6,7,8-octahydro-1,4:5,8- dimethanoanthracen-9-yl)porphyrin] and [Ru VI(D 2-Por)O 2] complexes. The mechanism of alkene epoxidation by [Ru VI(Por)O 2] has been examined. Procedures for catalytic epoxidation of alkenes using ruthenium porphyrin catalysts has also been developed. [Ru VI(Por)(NTs) 2] was found to undergo aziridination of alkenes and amidation of alkanes in organic solvents at room temperature. ©1999 IUPAC.published_or_final_versio

Better working memory and motor inhibition in children who delayed gratification

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Assessment of diastolic dysfunction by tissue Doppler echocardiography in patients with heart failure

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Clinical characteristics of viral infection of central nervous system in Queen Mary Hospital

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Assessment of regional systolic and diastolic impairment of left ventricular function: a study with tissue doppler imaging on right ventricular pacing

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Suppression of myocardial fibrosis by valsartan and monopril in animals after acute myocardial infarction

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Assessment of regional systolic and diastolic impairment on left ventricular function: a study with tissue Doppler imaging on right ventricular pacing

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Expression of Cyclooxygenase-2 Protein in Acute Myocardial Infarction

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Efficient white and red light emission from GaN/tris-(8-hydroxyquinolato) aluminum/platinum(II) meso-tetrakis(pentafluorophenyl) porphyrin hybrid light-emitting diodes

A study based on the analysis of white and red light emitted from GaN light-emitting diodes was presented. The enhancement in the light emission efficiency was brought about by the employing of an aluminum based hybrid material, tris-(8-hydroxyquinolato) aluminum. The luminescence conversion (LC) efficiency of the LEDs were observed to be 3.3% for white LC-LED and 4.0% for red LC-LED, respectively.published_or_final_versio