A combinatorial in situ three-component chiral oxazoline-Schiff base copper(II) complex catalyst formation method was developed. This simple combinatorial chiral catalyst approach provided a modular library of chiral oxazoline-Schiff base copper(II) complex catalysts. The catalytic activity of these in situ generated catalysts can be rapidly and conveniently evaluated in the asymmetric Henry re...

freshly prepared zno nanoparticles were used as an effective heterogeneous base catalyst for the synthesis of aryloximes. the conversion of arylaldehydes and arylketones into the corresponding oximes (up to quantitative yields) was achieved by simply mixing the liquid reactants and hydroxylamine hydrochloride with zno nanoparticles under solvent-free condition. the procedure was carried out und...

We report herein the use of a dual catalytic system comprising a Lewis base catalyst such as quinuclidin-3-ol or 4-dimethylaminopyridine and a photoredox catalyst to generate carbon radicals from either boronic acids or esters. This system enabled a wide range of alkyl boronic esters and aryl or alkyl boronic acids to react with electron-deficient olefins via radical addition to efficiently for...

We report the first catalyst based on palladium for the reaction of CO2, alkene and a base to form sodium acrylate and derivatives. A mechanism similar to a previously reported Ni(0)-catalyst is proposed based on stoichiometric in situ NMR experiments, isolated intermediates and a parent palladalactone. Our palladium catalyst was applied to the coupling of CO2 with conjugated alkenes.

A heterogeneous catalyst containing manganese Schiff base complex (derived from 2,4-dihydroxybenzadehyde and 1,2-phenylenediamine) is produced by covalent anchoring in MCM-41 matrix. The synthesized catalyst was characterized by X-ray diffraction pattern (XRD), inductivity coupled plasma (ICP), Fourier transform infrared (FT-IR) spectroscopy, N2 sorbtion-desorbtion isotherm and by tr...

Catalytic enantioselective monosilylations of diols and polyols furnish valuable alcohol-containing molecules in high enantiomeric purity. These transformations, however, require high catalyst loadings (20-30 mol%) and long reaction times (2-5 days). Here, we report that a counterintuitive strategy involving the use of an achiral co-catalyst structurally similar to the chiral catalyst provides ...

In the course of developing an enantioselective, Lewis base/Brønsted acid co-catalyzed carbosulfenylation of alkenes, a seemingly impossible conundrum arose: How could a catalyst inhibit a stoichiometric reaction? Despite the observation of very good enantioselectivities, the rate of the uncatalyzed reaction (i.e., no Lewis base) was found to be comparable to or slightly faster than that of the...

Methanol, formaldehyde, carbon monoxide, and propylene conversion were examined in a laboratory flow reactor over three base-metal containing alumina-supported palladium (Pd) catalysts in addition to Pd on y-alumina catalyst. The base metals were cerium, barium, and a combination of the two. Experiments were performed to determine the effect of air to fuel ratio on lightoff temperatures of vari...

bamboo-structured carbon nanotubes are grown on co-mo/mcm-41 catalyst in the temperature range of 873-973 k by thermal chemical vapor deposition of acetylene. this study shows that the purified carbon nanotubes have open tips and the metals of the catalyst are not encapsulated. thus, the bamboo-structure seems to grow from the base. pore size distribution of the product is quite narrow and is i...