作者:Alan R. Katritzky、Wolfgang H. Ramer、Jamshed N. Lam
DOI:10.1039/p19870000775
日期:——
1-(Phenylthiomethyl)benzimidazole is lithiated initially at the 2-position and at low temperatures the 2-lithio derivative reacts with active electrophiles to form 2-substituted products. At higher temperatures rearrangement occurs to a rather unstable methylene-lithiated isomer, which can be trapped by weaker electrophiles. Lithiation can be directed exclusively to the methylene group by: (a) using
1-(苯基硫代甲基)苯并咪唑最初在2位被锂化,在低温下,2-lithio衍生物与活性亲电试剂反应形成2-取代的产物。在较高的温度下,重排发生了相当不稳定的亚甲基化的异构体,该异构体可能会被较弱的亲电试剂捕获。可以仅通过以下方式将锂化直接导向亚甲基:(a)使用相应的亚砜或砜,或(b)用叔丁基或苯基(非甲基)封端2位。