Development of a Candidate Reference Method for the Simultaneous Quantitation of the Boar Taint Compounds Androstenone, 3α-Androstenol, 3β-Androstenol, Skatole, and Indole in Pig Fat by Means of Stable Isotope Dilution Analysis–Headspace Solid-Phase Microextraction–Gas Chromatography/Mass Spectrometry
Iron-Catalyzed Methylation Using the Borrowing Hydrogen Approach
作者:Kurt Polidano、Benjamin D. W. Allen、Jonathan M. J. Williams、Louis C. Morrill
DOI:10.1021/acscatal.8b02158
日期:2018.7.6
developed using methanol as a C1 building block. This borrowing hydrogen approach employs a Knölker-type (cyclopentadienone)ironcarbonyl complex as catalyst (2 mol %) and exhibits a broad reaction scope. A variety of ketones, indoles, oxindoles, amines, and sulfonamides undergo mono- or dimethylation in excellent isolated yields (>60 examples, 79% average yield).
Rhenium(I)-Catalyzed C-Methylation of Ketones, Indoles, and Arylacetonitriles Using Methanol
作者:Sujan Shee、Sabuj Kundu
DOI:10.1021/acs.joc.1c00376
日期:2021.5.7
A ReCl(CO)5/MeC(CH2PPh2)3 (L2) system was developed for the C-methylation reactions utilizing methanol and base, following the borrowing hydrogen strategy. Diverse ketones, indoles, and arylacetonitriles underwent mono- and dimethylation selectively up to 99% yield. Remarkably, tandem multiple methylations were also achieved by employing this catalytic system.
Thioether Adducts of a New Imine Reactive Intermediate of the Pneumotoxin 3-Methylindole
作者:Konstantine W. Skordos、John D. Laycock、Garold S. Yost
DOI:10.1021/tx9801209
日期:1998.11.1
deuterated analogues of 3-methylindole to trap the imine intermediate as its thioether conjugates. The N-acetylcysteine conjugate of 3-hydroxy-3-methylindolenine was detectable by LC/MS, but a molecular ion was not observed because the adduct rapidly dehydrated to form the 2-substituted indole. However, the imine was S-alkylated, and the intermediate carbinol was intramolecularly trapped using thioglycolic
Synthesis of deuterium-labeled d3-androstenone and d3-skatole for boar taint analysis
作者:Jochen Fischer、Paul W. Elsinghorst、Matthias Wüst
DOI:10.1002/jlcr.1895
日期:2011.7
The steroidal pig pheromone androstenone (5α-androst-16-en-3-one) as well as the indole derivate skatole are known to be the major compounds contributing to boar taint. The preparation of 2H-labeled internal standards of androstenone and skatole for stable isotope dilution assay–gas chromatography–mass spectrometry analysis of pig back fat samples is presented. The synthesis of d3-androstenone is highlighted by a palladium catalyzed deuteration of a Δ5,6-double bond of a hydrophobic steroid in a polar, D2O-containing solvent mixture. Moreover, the utilization of D2O as a deuterium source with in situ formation of D2 by means of Mg0 was found to be a very feasible and convenient alternative with respect to costs and technical effort.