A catalytic enantioselective vinylogous domino reaction has been achieved from ketone-derived benzylidene Meldrum's acid and ?-ketolactones to provide spirolactone dihydropyranones with more than 99% ee. An Auto Tandem Catalysis (ATC) process resulting dual complementary role of (DHQ)2PHAL organocatalyst resulted in a sequence involving an asymmetric formal (4+2) cycloaddition the subsequent ki...

this study reports the synthesis of chitosan anchored schiff base, ([2-oxo-1h-indol-3-ylidene] amino) chitosan and its cu (ii) metal complex. the complex was characterized by elemental analysis, ft-ir spectrum, thermogravimetry analysis .the crystallinity of the compound was analyzed by powder x-ray diffraction technique. the catalytic efficiency of complex was studied in the oxidation of alcoh...

an efficient synthetic method for successful synthesis of amine denderon on sba-15 and related pd (ii) complex has been developed. this modified mesoporous material was characterized by various techniques such as tem, xrd, atomic absorption spectroscopy, n2 adsorption-desorption, and ft-ir. the catalytic activities of the prepared catalysts were investigated by employing aerobic oxidation of al...

Palladium-catalyzed oxidation can single out the secondary hydroxyl group at C3 in glucose, circumventing the more readily accessible hydroxyl at C6 and the more reactive anomeric hydroxyl. Oxidation followed by reduction results in either allose or allitol, each a rare sugar that is important in biotechnology. Also, N-acetylglucosamine is selectively oxidized at C3. These results demonstrate t...

Tandem oxy-Cope and transannular vinylogous aldol reactions and/or vinylogous retro-aldol, conjugate addition, and transannular vinylogous aldol reactions transformed some tricyclic vinyl enones into fused tetracycles under basic conditions. Mesylates derived from similar tetracyclic products underwent efficient skeletal reorganization via transannular ring-opening but then different modes of t...

a catalytic spectrophotometric method for determination of ultra-trace quantities of manganese(ii) id described. the method is based on the catalytic effect of manganese(ii) on the oxidation reaction of ferroin by potassium periodate in acidic media. the reaction is monitored spectrophotometrically at 510 nm by a slope method and mn(ii) is determinable in the range of 1-1000ngml-1. the limit of...

The vanadium-based catalyst, acts as a homogeneous catalyst for the selective oxidation of various kinds of sulfides with 30% aqueous H2O2. Vanadium-based catalyst was successfully used as the oxygen source for the oxidation of sulfides to sulfoxides for the first time. The sulfoxides were obtained in a good way to high yields without any detectable over-oxidation to sulfones under normal condi...

we explore electro-catalytic properties of a system consisting of platinum and palladium nanoparticles dispersed over a nanotubular self-organized tio2 matrix. these electrodes prepared by electroess and microemulsion of palladium and palladium nanoparticles on to tio2 nanotubes, respectively. titanium oxide nanotubes were fabricated by anodizing titanium foil in ethylene glycol (eg) fluoride-c...

The reaction of a silyl dienolate, Cu(II) salt and TBAT yielding the corresponding copper dienolate is addressed. A combined NMR cyclic voltammetry analysis first highlight role in to Cu(I) reduction structure precatalytic species. From these results second set theoretical studies enable determination mechanism formation catalytic Finally, we showed that catalyst promote E/Z s-cis/s-trans equil...