the effects of confinement in carbon nanotubes on fischer-tropsch (ft) activity, selectivity and lifetime of carbon nanotubes (cnts) supported iron catalysts are reported. a method was developed to control the position of the catalytic sites on either inner or outer surface of carbon nanotubes. tem analyses revealed that more than 80% of iron oxide particles can be controlled to be positioned a...

Catalytic action of Ni atoms in the growth of single-wall carbon nanotubes is investigated using tight-binding molecular dynamics and ab initio methods. Our results demonstrate this to be a two step process in which the Ni atom first creates and stabilizes defects in nanotubes. The subsequent incorporation of incoming carbon atoms anneals the Ni-stabilized defects freeing the Ni atom to repeat ...

The catalytic highly regio-, diastereo-, and enantioselective synthesis of a small library of spiropyrrolizidineoxindolesvia a four-component 1,3-dipolar cycloaddition reactionof azomethineylides, derived from isatin, with electron-deficient dipolarophilewas described. The process occurs at room temperature in aqueous ethanol as a green solvent and in the presence of a bidendatebis(imi...

An array of aromatic aldehydes with electron withdrawing groupunderwent crossed-Aldol condensation with cycloalkanone in the presence of catalytic amounts of DBSA under aqueous media to afford the corresponding α, ά-bis(substituted-benzylidene) cycloalkanones in good yields. The electronic effects on aromatic aldehydes could be observed. The present method is operationally simple and use of wat...

A sequential process strategy was introduced for the synthesis of 2,3,4,5-tetrasubstituted pyrroles by the formation of benzoin from the corresponding aromatic aldehyde and followed by condensation reaction with 1,3-dicarbonyl compounds and ammonium acetate in the presence of diethylene glycol-bis(3-methylimidazolium) dihydroxide as catalyst in refluxing ethanol. The recycled catalyst could be ...

The catalytic highly regio-, diastereo-, and enantioselective synthesis of a small library of spiropyrrolizidineoxindolesvia a four-component 1,3-dipolar cycloaddition reactionof azomethineylides, derived from isatin, with electron-deficient dipolarophilewas described. The process occurs at room temperature in aqueous ethanol as a green solvent and in the presence of a bidendatebis(imi...

We report a catalytic asymmetric reaction process that involves the use of solid-phase reagents and catalysts that constitute the packing of a series of "reaction columns". This process was applied to the catalytic asymmetric synthesis of beta-lactams, to yield pure products with excellent enantio- and diastereoselectivity. We have identified several advantages to conducting chemical reactions ...

The advantages in using catalytic hydrophobic membranes in bioreactors operating under non-isothermal conditions, process of thermodialysis, for remediation of aqueous systems polluted by Endocrine Disruptors are discussed and illustrated. In presence of a transmembrane temperature gradient the enzyme activity increases along the yield of the bioremediation process. The theoretical bases accoun...

Electroless plating is a chemical reduction process which depends upon the catalytic reduction of a metallic ion in an aqueous solution containing a reducing agent without the use of electricity (1). Cahill (2) showed that the cupric ion could be reduced autocatalytically with formaldehyde in an alkaline solution. Okinaka (3 ) established that the overall reaction of the catalytic copper platin...

in the present work, impact of lewis acid (la) catalysts bf3, bcl3, and bbr3 on the kinetics andregioselectivity of 1,3-dipolar cycloaddition (1,3-dc) reaction between azidobenzene and acroleinwas theoretically studied using b3lyp/6-31g* level. our results indicate while the uncatalyzed 1,3-dc reaction under investigation takes place via a non-polar, non-regioselective, and lowasynchronous proc...