Kinetics of the precipitation of palladium dimethylglyoximate from homogeneous solution.
The kinetics of formation of palladium dimethylglyoximate in the post-nucleation and pre-nucleation stages, and the effect of palladium on the reaction of biacetyl and hydroxylamine, have been studied.
The oximation of biacetyl
Abstract Spectrophotometric evidence indicates that the reaction of biacetyl with hydroxylamine proceeds through the formation of two carbinolamine intermediates. The second of these intermediates is also encountered in the reaction of biacetyl monoxime with hydroxylamine. The rate-limiting step in the oximation of biacetyl is the slow dehydration of the initially formed intermediate, as is evidenced from the various rate constants obtained for the two reactions over the range 0–10°. When niekel(II) is present in the biacetyl-hydroxylamine system, the formation of nickel dimethylglyoximate proceeds by two independent mechanisms, whereas only a single mechanism is responsible for precipitate formation in the biacetyl monoxime-hydroxylamine system.
Catalytic removal of tert-butyldimethylsilyl (TBS) ether by PVP-I
Abstract A mild, efficient and rapid protocol the deprotection of alcoholic TBDMS ethers using PVP-1 as catalyst in methanol, the procedure of deprotection of various TBDMS ethers were found to be very convenient, easy work-up, high yielding.