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

1,4-Dibenzyl-1,4-diazoniabicyclo[2.2.2]octane chlorochromate (DBDABOCC): A mild and selective reagent for efficient oxidation of organic compounds under non-aqueous conditions

863-866The preparation of 1,4-dibenzyl-1,4-diazoniabicyclo[2.2.2]octane chlorochromate 1 is described. With this reagent benzylic and allylic alcohols are selectively oxidized to their corresponding carbonyl compounds in excellent yields. Oximes, thiols and aromatic amines are also converted to their corresponding carbonyl compounds, disulfides and azo compounds efficiently

Bis(1-benzyl-4-aza-1-azonia-bicyclo[2.2.2]octane) persulfate: A mild and efficient oxidant for cleavage of oxime double bonds under anhydrous conditions

221-224Bis( 1-benzyl-4-aza-1-azoniabicyclo[2.2.2]octane)persulfate (BAABCPS) 1 readily prepared as orange solid from commercially available 1,4-diazabicyclo[2.2.2]octane (DABCO) and potassium persulfate, converts oximes and a-sulfinyl oximes to the corresponding carbonyl compounds and β<span style="font-size:12.5pt;mso-bidi-font-size:6.5pt;font-family: HiddenHorzOCR;mso-bidi-font-family:HiddenHorzOCR">-keto sulfoxides respectively, the yields and enantiomeric purity are excellent.<span style="font-size:16.0pt; mso-bidi-font-size:10.0pt"> </span

Selective conversion of thioamides and thioureas to their oxygen analogues using quinolinium fluorochromate

2638-2640The synthetic utility of quinolinium f1uorochromate (QFC) in deprotection of thiocarbonyl compounds is reported. A variety of primary and secondary thioamides and thioureas are converted to their oxo derivatives in high yields. However, tertiary thioamides afford their amides in relatively poor yields. Selective deprotection of thioamides and thioureas in the presence of thionoesters and thioketones is noteworthy advantage of this method