Diverse Reactions of 1,4-Dilithio-1,3-dienes with Nitriles: Facile Access to Tricyclic Δ1-Bipyrrolines, Multiply Substituted Pyridines, Siloles, and (Z,Z)-Dienylsilanes by Tuning of Substituents on the Butadienyl Skeleton
作者:Nan Yu、Congyang Wang、Fei Zhao、Lantao Liu、Wen-Xiong Zhang、Zhenfeng Xi
DOI:10.1002/chem.200701742
日期:2008.6.20
4-tetrasubstituted 1,4-dilithio-1,3-dienes (Type I) with four equivalents of various aromatic nitriles in the presence of hexamethylphosphoramide (HMPA) gives exclusively fully substituted pyridines in moderate to good yields. Similarly, trisubstituted pyridines can be prepared by the reaction of 2,3-dialkyl- or diaryl-substituted 1,4-dilithio-1,3-dienes (Type II) with nitriles. However, five- or six-membered-ring
在六甲基磷酰胺(HMPA)存在下,将1,2,3,4-四取代的1,4-二硫代-1,3-二烯(I型)与四当量的各种芳族腈加成环化,可得到完全取代的吡啶,其中等至良品率高。类似地,三取代的吡啶可通过2,3-二烷基或二芳基取代的1,4-二硫代-1,3-二烯(II型)与腈反应制备。然而,五元或六元环稠合的2,3-二取代的1,4-二硫代-1,3-二烯(III型)与各种无α-氢原子的芳族和脂肪族腈反应,得到三环的Delta1-双吡咯啉高产。六元环稠合的2,3-二取代的1,4-二硫代-1,3-二烯(III型)与2-氰基吡啶的反应提供了相应的吡啶,没有观察到三环的Delta1-联吡咯啉。七元环稠合的二硫代二烯与PhCN或三甲基乙腈反应,以高收率提供相应的吡啶。当用Me3SiCN处理1,2,3,4-四取代的二硫代试剂(I型)时,很容易发生串联甲硅烷基化/分子内取代过程,生成甲硅烷基,而2,3-二取代的二硫代试剂(II和III型)反应)与Me