以β-硝基苯乙烯衍生物为底物，二溴海因为氮源/卤素源，乙腈作溶剂，建立了碳碳双键上高度区域选择性氨溴加成反应新体系。β-硝基苯乙烯衍生物与二溴海因在室温无水碳酸钠催化下反应，可高收率获得邻位氨溴加成产物，最高收率达97%；β-甲基-β-硝基苯乙烯衍生物在氢氧化钾催化下回流反应，也可高收率得到邻位氨溴加成产物，最高收率达95%。实验结果表明，对于硝基苯乙烯衍生物，当苯环4-位具有强供电子基团如CH3 O时，可以得到单一的α-氨基-β-溴加成产物，但其收率相对较低；当硝基苯乙烯衍生物的苯环4-位有强吸电子基团如NO2时，反应收率则很高。这一实验结果证明β-硝基苯乙烯衍生物(缺电子烯烃)与二溴海因的氨溴加成反应具有亲核加成的特征。本文共考察了20种不同结构的β-硝基苯乙烯衍生物的氨溴加成反应情况，其产物结构经核磁共振波谱及质谱分析确证，并提出了可能的反应机理。%A new protocol for the high regioselective aminobromination of β-nitrostyrene derivatives with 1 ,3-dibromo-5,5-dimethyl hydantoin(DBDMH) as nitrogen/bromine sources was developed. Two kinds ofβ-nitro-styrene derivatives got different reaction results under different reaction conditions. For the β-nitrostyrene de-rivatives, this protocol offered vicinal haloamine products in good to excellent yields( up to 97%) at room tem-perature in CH3 CN catalyzed by Na2 CO3 . For the β-methyl-β-nitrostyrene, the good to excellent yields( up to 95%) were also achieved refluxed in CH3 CN catalyzed by KOH. The strong electron-donating substituents ( e. g. , CH3 O) on the 4-position of benzene ring could deactivated the reaction activity of β-nitrostyrenederi-vetives with DBDMH. However, the vicinal haloamines were also afforded as the sole addition product. Whereas strong electron-withdrawing substituent( e. g. , NO2 ) could activated reaction activity remarkably and the vicinal haloamines were afforded as the sole addition product, too. The result revealed that the addition re-action has a nucleophilic addition feature. The aminobromination of 20 examples ofβ-nitrostyrenes were inves-tigated in this work and the structure of all products were confirmed by the corresponding 1 H NMR, 13 C NMR spectra and HRMS( ESI) . A possible mechanism involving a nucleophilic conjugate addition was proposed.
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