Research On The Selective Nitration Of Anilides And Acrylamides

Direct and selective functionalization of alkyl, alkenyl and aryl C-H bonds has been a long-standing challenge in synthetic chemistry. The ubiquity and relatively low cost of hydrocarbons makes C-H bond functionalization an attractive alternative to classical cross-couping reactions, which usually requires organohalides and organometallic reagents. In addition, C-H activation provides an atom economical synthetic strategy and reduces the production of toxic byproducts which contributes to the growing field of reactions with decreased environmental impact.Nitroarenes and nitroolefins have been widely used as key intermediates in synthetic organic chemistry and for the generation of explosives, dyes and pharmaceuticals. The mixed acid system (HNO3/H2SO4) as the nitrating reagents is usually used in the classical electrophilic nitration. However, these protocols suffer a lot of problems such as low regio-selectivity, harsh reaction conditions and limited functional group tolerance. In recent years, lots of methods are developed using metal salts as the nitrating reagents, but the metal reagents also have the disadvantages such as difficult to processing and environmental unfriendly. Therefore, the development of metal free reagent for selective nitration methods has great mean and necessity.Based on the above two considerations, the research work of this thesis include the following two parts:1. Directed Nitration of Anilides by tert-Butyl Nitrite Leading to the Synthesis of NitroarenesEfficient copper-catalyzed nitration of anilides using TBN (tert-butyl nitrite) as a nitrating reagent is developed, the method possess the advantages such as high functional group tolerance, good to excellent yields, mild reaction condition and wide substrate scope. According to the control experiment and some related literatures, a radical mechanism involved the SET process of copper was proposed.2. Directed Nitration of Acrylamides by tert-Butyl Nitrite Leading to the Synthesis of NitroolefinsIn this chapter, a chemoselective and steroselective method to synthesize nitroolefins by TBN (tert-butyl nitrite) was developed. The reaction can occur at room temperature and the products own a perfect E-configuration. In the screening of the substrate scope, it was found that the electronic effect and steric effect had no significant influence on the reactivity. Meanwhile, according to the radical trapping experiment, a plausible mechanism was proposed.