A diversified family of enantiopure P-stereogenic "R-SMS-Phos" {R-SMS-Phos = 1,2-bis[(o-RO-phenyl)(phenyl)phosphino]ethane} ligands wherein R = branched or heteroatom-substituted alkyl, aralkyl, silyl, acyl, sulfonyl, etc. was screened for the Rh(I)-catalyzed hydrogenation of a representative set of olefinic substrates. This systematic and detailed investigation revealed a marked beneficial imp...

Using rational ligand design, we have developed of a second-generation ligand, bis(3,5-di-tert-butylphenyl)(tert-butyl)phosphine, for the preparation of allylsilanes using the palladium-catalyzed silyl-Heck reaction. This new ligand provides nearly complete suppression of starting material alkene isomerization that was observed with our first-generation catalyst, providing vastly improved yield...

In a straightforward and fast protocol, a mixture of 1,3-dimethylimidazolium fluoride ([DMIM]F) and 1-butylimidazolium tetrafluoroborate ([Hbim]BF₄) efficiently catalyzed the reaction of epoxides with ketene silyl acetals (KSA) to give various γ-lactones under metal-free conditions. Diverse kinds of the desired γ-lactones were directly prepared with high regioselectivities and yields in a simpl...

The metal-free catalytic hydrogenolysis of silyl triflates and halides (I, Br) to hydrosilanes is unlocked by using arylborane Lewis acids as catalysts. In the presence a nitrogen base, catalyst acts Frustrated Pair (FLP) able split H2 generate boron hydride intermediate capable reducing (pseudo)halosilanes. This organocatalytic system competitive with metal-based catalysts enables formation va...

Abstract Chromate ions CrO 4 −2 have been used in three simples, rapid, an accurate spectrophotometric method. These methods were suggested to estimate mefenamic acid its pure form and pharmaceutical preparations. different from each other with reactants components, they are similar as, indirect depends on oxidation – reduction reaction. So that, Method 1, based reaction between chromate ion pr...

in this research, different alcohols and phenols are subjected to the reaction with hmds in the presence of ionic liquid and silica-supported catalysts. silylation was accomplished under mild reaction conditions at room temperature in short reaction times and good to excellent yields.

alumina-supported cs3[re(c2o4)3] precursor has been synthesized  for preparation of re-cs/g-al2o3 catalyst. cs3[re(c2o4)3]  has been prepared from the reaction of recl3 with  h2c2o4.2h2o and cscl in water. the complex has been characterized by elemental analysis and various spectroscopy techniques such as ft-ir, uv-vis and 13c-nmr. the complex was supported on γ-al2o3 by column chromatography. ...

we have reported the fabrication of boric acid incorporated into surface of magnetite nanoparticles. the catalyst was characterized using spectroscopic, magnetic and thermal techniques (ft-ir, sem, xrd, icp, vsm and tga). it catalyzed mukaiyama aldol reaction of a ketene silyl acetal type nucleophile ((1-methoxy-2-methylprop-1-enyloxy) trimethylsilane), and various aldehydes (aromatic, aliphati...

In the silyl Lewis acid-promoted Mukaiyama aldol reaction, the steric and electronic properties of the silyl group on the silyl Lewis acid influence the reaction mechanism and product distribution. When super silyl triflates such as (TMS)3SiOTf and (TES)3SiOTf are used as Lewis acids, the silyl group of the silyl enol ether chemoselectively transfers to the product. The mechanistic details have...