The reaction of 2,3-dibromothiophene with 1 equivalent of lithium diisopropylamide at -80°C, followed by addition of an electrophile (methyl iodide, methanol, allyl bromide, dimethylformamide, cyclohexanone) gives 2-substituted 3,5-dibromothiophenes selectively and in high yields. The substitution pattern of all products was confirmed by unambiguous assignment of all C-atoms via 13C-NMR spectrometry.
在 -80°C 下,
2,3-二溴噻吩与 1 个等量的
二异丙基酰胺
锂发生反应,然后加入亲电体(甲基
碘、
甲醇、烯丙基
溴、二甲基甲酰胺、
环己酮),可选择性地高产出 2-取代的 3,5-二
溴噻吩。通过 13C-NMR 光谱法对所有 C 原子进行明确分配,确认了所有产物的取代模式。