Ruthenium-catalyzed intramolecular cyclization of diazo-β-ketoanilides for the synthesis of 3-alkylideneoxindoles
作者:Wai-Wing Chan、Tsz-Lung Kwong、Wing-Yiu Yu
DOI:10.1039/c2ob06985g
日期:——
With [Ru(p-cymene)Cl2]2 as catalyst, diazo-β-ketoanilides would undergo intramolecular carbenoid arene CâH bond functionalization to afford 3-alkylideneoxindoles in up to 92% yields. The reaction occurs under mild conditions and exhibits excellent chemoselectivity. The lack of primary KIE (kH/kD â¼ 1) suggests that the reaction should not proceed by rate-limiting CâH bond cleavage; a mechanism involving cyclopropanation of the arene is proposed.
以[Ru(p-cymene)Cl2]2为催化剂,二氮-β-酮酰苯胺类化合物可以进行分子内卡宾型芳香C-H键官能团化反应,最高产率达92%的3-烷叉基氧吲哚。该反应在温和条件下进行,并显示出优异的化学选择性。缺乏初级同位素效应(kH/kD ≈ 1)表明反应不会通过速率限制的C-H键断裂进行;提出了一种涉及芳香环的环丙烷化反应机理。