RESUMO
Owing to the ubiquity of the hydroxyl group, reductive deoxygenation of alcohols has become an active research area. The classic Barton-McCombie reaction suffers from a tedious two-step procedure. New efficient methods have been developed, but they have some limitations, such as a narrow substrate scope and the use of moisture-sensitive Lewis acids. In this work, we describe the Ph3P/ICH2CH2I-promoted reductive deoxygenation of alcohols with NaBH4. The process is applicable to benzyl, allyl and propargyl alcohols, and also to primary and secondary alcohols, demonstrating a wide substrate scope and a good level of functional group tolerance. This protocol features convenient operation and low cost of all reagents.
RESUMO
In this study, detection of 20 FITC-derivatized amino acids using an MEEKC-LIF was demonstrated. In order to achieve good separation for hydrophobic amino acids, the MEEKC method was employed and detection limits were obtained in the range of 0.32-2.2 nM, which is comparable to previous reports on amino acid analyses. Furthermore, a significant reduction in the reaction time from 1 h for conventional derivatization to 3 min for the microwave-assisted derivatization was observed and achieved, as opposed to the traditional pretreatment of real sample due to its complexity prior to the analysis of amino acid content. Finally, this microwave-assisted derivatization MEEKC-LIF method successfully determined amino acids in beverage, food, and biological samples (rat brain) with good recovery.