Research On The Difunctionalization Reaction Of Organoselenium Reagents With Alkenes And The Application Of Fast Gas Chromatography In The Quality Control Of Flavors And Fragrances

As a basic structural moiety,amide widely exists in many bioactive natural products and pharmaceuticals.Therefore the carbon-nitrogen bond forming reaction has become one of the key steps in organic synthesis.In addition,during the last few decades,organoselenium compounds have been drawn much attention in organic synthesis since they have a variety of biological activities such as anticancer,antivirus,and anti-aging activities.The organoselenium reagents,especially the electrophilic organoselenium reagents provide an efficient access to a carbon-heteroatom bond by heteroatom with lone pair electrons attacking a three-membered ring episelenonium ion via an intermolecular or an intramolecular electrophilic addition reaction.The reaction usually accompanies with the formation of chiral carbon centers and cyclic compounds.Among these addition reactions,the reaction of heteroatomic nucleophiles with poor nucleophilicity such as amide with the episelenonium ion is still a big challenge in selenium chemistryFlavors and fragrances have been widely used in pharmaceutical,food,and tobacco industries in order to spark consumers'senses.Those adulterate flavors and fragrances available in the market,howerer,may deteriorate the flavors and fragrances' quality and lead to potential hazard to the consumers'health.Therefore,to develop a fast and accurate analytical method of identification of flavors and fragrances is still a big challenge we face.The first part of our work involves Lewis acid-catalyzed intermolecular addition of simple alkenes with N-phenylselenophthalimide.A method for the simple,efficient,and atom-economic amidoselenenylation of simple alkenes under mild conditions using TiCl4 as a catalyst and N-(phenylseleno)phthalimide as both a nitrogen and selenium source was developed.A broad range of olefins can be applied to afford vicinal amidoselenides in good yield and with high regioselectivity and diastereoselectivity;the regioselectivity and diastereoselectivity of the amidoselenenylated products were also verifiedThe second part of our work involves the application of rapid gas chromatography electronic nose on recognition of winning sample from the bidding samples.Firstly,collect the chromatograms about the standard samples and the tender samples on two column.Secondly,use the principal component analysis(PCA)method and convert the original data vector to linear,and the sample of the smallest Mahalanobis are determined to be the winning sample.This method is simple,convenient,rapid and "full scan without blind area".It can accurately identify the closest sample to the quality between the test sample and the standard sample.