a mild, efficient and fast method for the oxidation of alcohols and trimethylsilyl, tetrahydropyranyl and methoxymethyl ethers to their corresponding carbonyl compounds using cro3 in the presence of rice husk ash (rha) is reported. all reactions were performed at room temperature in high to excellent yields. a new, efficient and green catalyst, heterogeneous reaction conditions, easy work-up of...

A two-step protocol allowing the C?H amination of cyclic ethers with iminoiodinanes, followed by reduction resulting intermediate has been developed for preparation amino alcohols. The initial functionalization is accelerated visible light, improving reactivity compared to thermal process performed in dark. effect different substituents on photochemical iminoiodinanes studied both experimentall...

The catalytic hydrosilylation of highly hindered and functionalized ketones is described. The combination of inexpensive catalyst precursors, CuCl and NHC.HX (NHC = N-heterocyclic carbene), leads to a highly efficient reduction mediator for the preparation of silyl ethers from unfunctionalized and functionalized alkyl, cyclic, bicyclic, aromatic, and heteroaromatic ketones. A series of catalyst...

A catalytic method for the direct cross-coupling of alkenyllithium reagents with aryl and alkenyl halides is described. The use of a catalyst comprising Pd2(dba)3/XPhos allows for the stereoselective preparation of a wide variety of substituted alkenes in high yields under mild conditions. In addition (1-ethoxyvinyl)lithium can be efficiently converted into substituted vinyl ethers which, after...

A catalytic method for the direct cross-coupling of alkenyllithium reagents with aryl and alkenyl halides is described. The use of a catalyst comprising Pd2(dba)3/XPhos allows for the stereoselective preparation of a wide variety of substituted alkenes in high yields under mild conditions. In addition (1-ethoxyvinyl) lithium can be efficiently converted into substituted vinyl ethers which, afte...

Using Raman spectroscopy without any preparation, we analyzed the brominated flame retardant, polybromodiphenyl ethers (PBDEs), which has been prohibited by the European Union. The typical Raman bands of PBDEs, which are clearly different from those of other brominated flame retardants, are from 100 to 300 cm(-1). In our analysis, the detection limit was about 100 ppm, and the analysis took abo...

Various derivatives of vitamin A, especially esters and ethers , have been studied by many investigators. However, its macromolecular derivatives have scarcely been reported. An attempt was made by the authors to synthesize the macromo lecular derivatives of vitamin A by preparation of the polymerizable derivatives , followed by their polymerization . Thus vitamin A acrylate, methacrylate, crot...