| The aminohalogenation is a reaction that converts common petroleum olefins into vicinal haloamine products by the addition of amine and halogen moieties onto carbon-carbon double bonds. Under certain conditions, the adductive products of aminohalogenation can be converted into useful molecular by its high Regio-and Stereoselective, the converting is a nucleophilic substituentional reaction of intermolecular or intramolecular. The aminohalogenation has become an interesting topic in modern organic synthesis and pharmaceutical molecular synthesis for nearly 40 years because of its important application. At present, the researchers are interested in the topics as follows:The research for expanding substrate scopes, e. g.α,β-unsaturated ketones, cinnamates, simple olefins, unsaturated nitrostyrenes and unsaturated nitriles. The research for screening various halogen/nitrogen sources, for example:now, we mainly use N, N-dichlorotoluene sulfonamide, N-bromoacetamide, the combination of N-bromosuccinimide and p-toluene sulfonamide as halogen/nitrogen sources. The research for explore new catalysts; the catalysts are believed to play a key role in the research of aminohalogenation. However, these catalysts still have several shortcomings, such as high molecular weight, hygroscopicity, high cost, and high catalyst loadings. Therefore, the work of choice and the study of the haloamino catalyst attract more and more attention in the chemical field.In this paper, we synthesized a series of bromoamino products at room temperature in acetone withβ-nitrostyrene as substrates and K3PO4 as the catalyst, NBS, acetamide as bromine and nitrogen sources. We also made a further explore on the catalytic effect of K3PO4 for the different substrate.The first chapter is a summary on research progress of the aminohalogenation and various catalysts'catalytic effect onα,β-unsaturated ketone,α,β-unsaturated esters, olefins andβ-nitrostyrene.In the chapterⅡ, the new system of the haloamino addition reaction ofβ-nitrostyrene has been described in which K3PO4 is as catalyst, acetamide is as nitrogen source, NBS is as bromine source. The structure of these products was characterized by elemental analysis,1H NMR and 13C NMR. The reaction active of the substrates was investigated through experiments and theseβ-nitrostyrene in which the NO2 bearing at the 4-position of benzene ring can afford a better yield with catalyst K3PO4. The reaction was completed within 1 h and afforded corresponding product in good yield (79%) when p-nitro-β-nitrostyrene reacted with acetamide and NBS catalyzed by K3PO4. Also, the yield can be reached to 51% when the benzene ring bearing electron-donating group, such as p-methoxy-β-nitrostyrene reacted with acetamide and NBS catalyzed by K3PO4 within 24 h.We have developed an easy and efficient method for the aminobromination ofβ-nitrostyrene derivatives catalyzed by anhydrous K3PO4 with combination of acetamide and NBS as the nitrogen/bromine sources in acetone. This protocol is convenient to be carried out at room temperature without protection with inert gases. The good chemical yields as well as high regiochemistry products have been obtained. These results indicate that unambiguously confirmed by X-ray crystal structure analysis, and the proposed possible mechanism can explain the high regiochemistry the reaction has characteristic of nucleophilic addition. The structure was of product well. Additionally, K3PO4 as the catalyst has the advantages of cheap, nontoxic, and readily available. |
