Synthesis of 2-(2,6-Dinitrophenyl)malonates, -acetates and acetonitrile by Copper-Mediated Vicarious Nucleophilic Substitution
作者:Olof Haglund、Martin Nilsson
DOI:10.1055/s-1994-25447
日期:——
A regioselective, vicarious nucleophilic substitution of 1,3-dinitrobenzene with α-bromo- and iodocarbanions proceeds in the presence of copper(I) tert-butoxide and pyridine giving 2,6-dinitrophenylmalonates, 2,6-dinitrophenylacetates or 2,6-dinitrophenylacetonitrile as the only isomers from bromomalonate esters, bromoacetate esters, iodoacetate esters or iodoacetonitrile, respectively. Without copper(I) tert-butoxide, the 4-substituted isomer is the only product. We believe that the reaction proceeds via a Ï-adduct of 1,3-dinitrobenzene and halocarbanion from which hydrogen and halogen are eliminated. This elimination is dependent upon the concentration of copper(I) tert-butoxide.
在叔丁醇铜(I)和吡啶存在下,1,3-二硝基苯与δ-溴-和碘-羰基离子发生了区域选择性的替代亲核取代反应,从溴丙二酸酯中得到了 2.6-二硝基苯丙二酸酯、2,6-二硝基苯乙酸酯或 2,6-二硝基苯乙腈作为唯一的异构体、2,6-二硝基苯丙二酸酯、2,6-二硝基苯乙酸酯或 2,6-二硝基苯乙腈,它们分别是溴丙二酸酯、溴乙酸酯、碘乙酸酯或碘乙腈的唯一异构体。在没有叔丁醇铜(I)的情况下,4-取代异构体是唯一的产物。我们认为,反应是通过 1,3-二硝基苯和卤代碳酸酯的 Ï-加成物进行的,其中的氢和卤素被消除。这种消除取决于叔丁醇铜(I)的浓度。