Intramolecular Aromatic Carbenoid Insertion of Biaryldiazoacetates for the Regioselective Synthesis of Fluorenes
作者:Jinho Kim、Youhwa Ohk、Sae Hume Park、Yousung Jung、Sukbok Chang
DOI:10.1002/asia.201100142
日期:2011.8.1
or copper‐catalyzed intramolecular aromatic carbenoid insertion of biaryldiazoacetates offers a convenient route to fluorene carboxylates with high yields. Whereas, thermal conditions provided a mixture of two regioisomeric products when substituted biaryldiazoacetates were employed as substrates. The developed catalytic conditions displayed an excellent level of regioselectivity, presumably owing to
铑或铜催化的双芳基重氮乙酸酯的分子内芳族类胡萝卜素插入提供了方便的途径,以高收率获得芴羧酸酯。然而,当使用取代的重芳基重氮乙酸酯作为底物时,热条件提供了两种区域异构产物的混合物。可能由于空间效应,发达的催化条件显示出极好的区域选择性。假定插入机理是亲电子芳族取代,这得到了初步的机理研究的支持。有效地合成了氯取代的芴衍生物,并将其用作胺的碱敏感保护基。