Showing papers on "Nickel boride published in 1987"
TL;DR: It has been shown that a combination of chlorotrimethylsilane and nickel boride effects the chemoselective reduction of an aldehyde in presence of a ketonic carbonyl group as discussed by the authors.
9 citations
TL;DR: Nickel boride selectively reductive cleavage of A-ring allylic lactone in Gibberellic acid methyl ester was described in this paper, where it was shown that it selectively reductively reduces the reduction of the lactone.
9 citations
Patent•
05 Oct 1987TL;DR: In this article, a novel alumina-supported nickel boride catalysts prepared by the borohydride promoted reduction of nickel arsenate are described and a method of catalyst preparation and process for hydrogenation of acetylenic and diolefinic compounds employing the invention catalysts are also described.
Abstract: Novel alumina-supported nickel boride catalysts prepared by the borohydride promoted reduction of nickel arsenate are described. Method of catalyst preparation and process for hydrogenation of acetylenic and diolefinic compounds employing the invention catalysts are also described.
2 citations
TL;DR: In this paper, the rate constants were derived from the slope of a least-squares fit of In [C/Co] vs. time data taken through at least four half-lives.
Abstract: siderations usually restricted initial concentrations of iodide salts to no more than 6 times the initial ether concentration for the most concentrated ether solutions used in the kinetic runs. For preparative scale cleavage reactions no problems were encountered when the iodide salts were not completely soluble at the start of the reaction. In the small scale reactions (2-8 mmol of ether) used to determine the kinetic rate constants, changes in the concentration of ethers and products with time were followed by analyzing aliquots by HPLC for compounds 1,2,3, and 6 or by quantitative proton NMR in CDC13 using 1-methylnaphthalene as the internal standard for compounds la, 4, 5, 7, 8, and 9. HPLC is more accurate and precise but requires tedious sample preparation in order to separate the analytes from iodide salts and solvent pyridine prior to injection onto the column. Quantitative NMR is less precise but requires no sample preparation. Rate constants for la determined by both methods agreed within experimental error. For the HPLC analyses, aliquots were quenched in aqueous H2S04, extracted with 1,2-dichloroethane, dried, diluted with acetonitrile, and concentrated on a Cl8 SepPak cartridge (Waters) prior to analysis on a CIS reverse-phase analytical column using an CH3CN/H20/HOAc (23/75/2) mobile phase. Pseudo-firstorder rate constants ( k , 8-l) were calculated from the slope of a least-squares fit of In [C/Co] vs. time data taken through at least 4 half-lives. Rate constant values reported in the table are averages of two or three reactions.
2 citations
1 citations