The ferrocene analogue of salicylic acid, 2-hydroxyferrocenecarboxylic acid was synthesized via monolithiation of ferrocene with t-butyllithium, and resolved to optically active forms. Optically active 2-hydroxyferrocenecarboxylic acid was converted to 1-hydroxyferrocenecarbaldehyde, ferrocene analogue of salicylaldehyde, and 2-alkoxyferrocenecarboxylic acids. The later compounds were used as chiral carboxylato ligands for the rhodium(II)-catalyzed asymmetric intramolecular C–H insertion of α-diazo β-keto esters (up to 42% ee).
水杨酸的
二茂铁类似物 2-hydroxyferrocenecarboxylic acid 是通过
二茂铁与 t-butyllithium 的单
锂化反应合成的,并被分解成具有光学活性的形式。具有光学活性的 2-羟基
二茂铁羧酸被转化为 1-羟基
二茂铁甲醛、
二茂铁类似物
水杨醛和 2-烷氧基
二茂铁羧酸。后来的化合物被用作手性羧基
配体,用于
铑(II)催化的 α-重氮 β-
酮酯的不对称分子内 C-H 插入反应(ee高达 42%)。