Contribution to the Study of the Mechanism of Directed Remote-Metalation. Evidence for the Intermediacy of a Geminal Dimetallo Dialkoxide C(OM)<sub>2</sub> (M = Li, K), First Doubly Charged Director of Ortho Metalation
作者:David Tilly、Subhendu S. Samanta、Asish De、Anne-Sophie Castanet、Jacques Mortier
DOI:10.1021/ol0474709
日期:2005.3.1
mechanism of the metalation of 2-biphenyl carboxylic acid (1) with the Lochmann-Schlosser superbase was determined by deuteriolysis. Both ortho (C(3)) and remote (C(2')) positions are metalated. The C(2')-metalated species 2 cyclizes instantaneously. Under suitable conditions, the doubly charged geminal dimetallo dialkoxide group C(OM)(2) 4 directs metalation in the adjacent position (C(1)), affording
通过氘代分解确定了Lochmann-Schlosser超碱与2-联苯羧酸(1)的金属化机理。邻位(C(3))和远端(C(2'))都被金属化。C(2')金属化的物种2瞬间环化。在合适的条件下,双电荷的双金属双金属双氧化物基团C(OM)(2)4指导相邻位置(C(1))的金属化,提供稳定的1-金属9H-芴-9,9-双金属二氧化物5在酸性处理后,可以被各种亲电试剂捕获,生成1个取代的9H-芴9-酮7和9。[结构:见文字]