n-Butyltriphenylphosphonium dichromate: An efficient and selective oxidizing agent

438-44

Palladium NanoparticlesImmobilized on Nano-silica Triazine Dendritic Polymer (Pdnp-nSTDP): An Efficient and Reusable Catalyst for Suzuki-Miyaura Cross-Coupling and Heck Reactions

A new catalyst based on palladium nanoparticles immobilized on nano-silica triazine dendritic polymer (Pdnp-nSTDP) was synthesized and characterized by FT-IR spectroscopy, thermogravimetric analysis, field emission scanning electron microscopy, energy dispersive X-ray, transmission electron microscopy and elemental analysis. The size of the palladium nanoparticles was determined to be 3.1±0.5 nm. This catalytic system showed high activity in the Suzuki–Miyaura cross-coupling of aryl iodides, bromides and chlorides with arylboronic acids and also in the Heck reaction of these aryl halides with styrenes. These reactions were best performed in a dimethylformamide (DMF)/water mixture (1:3) in the presence of only 0.006 mol% and 0.01 mol% of the catalyst, respectively, under conventional conditions and microwave irradiation to afford the desired coupling products in high yields. The Pdnp-nSTDP was also used as an efficient catalyst for the preparation of a series of star- and banana-shaped compounds with a benzene, pyridine, pyrimidine or 1,3,5-triazine unit as the central core. Moreover, the catalyst could be recovered easily and reused several times without any considerable loss of its catalytic activity

Efficient and selective deprotection of aryl aldehyde diacetates catalyzed by tin(II) chloride dihydrate

1223-1225A mild,efficient and excellent yield method for the selective deprotection of aryl aldehyde diacetates in the presence of .phenolic acetate and aliphatic aldehyde diacetate using catalytic amounts of tin(II) chloride dihydrate (SnCl2.2H2O) is described

Antimony trichloride; a mild, efficient and convenient catalyst for conversion of oxiranes to thiiranes under non-aqueous conditions

605-606<span style="font-size:12.0pt;font-family: " times="" new="" roman";mso-fareast-font-family:"times="" roman";mso-ansi-language:="" en-in;mso-fareast-language:en-in;mso-bidi-language:ar-sa"="" lang="EN-IN">Oxiranes are converted to their corresponding thiiranes in excellent yields (95-98%) using ammoniun thiocyailate and catalytic amounts of antimony trichloride.</span