Domino Oxidative [Pd]-Catalysis: One-Pot Synthesis of Fluorenones Starting from Simple Benzylamines and Iodo Arenes

A domino [Pd]-catalysis for the efficient synthesis of fluorenones is presented. The overall reaction proceeds through the formation of a five membered Pd­(II)-cycle via a highly regioselective ortho C­(sp2)-H activation(s) of simple benzylamine that combines with external iodo arenes to give ortho arylated products. Significantly, the reaction further activates the C­(sp3)-H and C­(sp2)-H (intramolecular oxidative Heck coupling) bonds to give tricyclic imine systems. Then the usual water workup affords the fused tricyclic ketones (fluorenones). Remarkably, this one-pot operation enabled the effective construction of two C–C to three C–C bonds

本文报道了一种可高效合成芴酮（fluorenones）的多米诺钯催化方法。该反应的整体历程为：以简单苄胺为底物，经高区域选择性的邻位C(sp²)-H活化形成五元钯(II)环，随后与外源性碘代芳烃结合得到邻位芳基化产物。值得注意的是，该反应可进一步活化C(sp³)-H与C(sp²)-H键（经分子内氧化Heck偶联），从而得到三环亚胺体系。随后经常规水洗后处理，即可得到稠合三环酮类产物（即芴酮）。尤为关键的是，该一锅法操作可有效构建2~3个碳碳键。