Alkylation of 1,3-dicarbonyl compounds with benzylic and propargylic alcohols using Ir–Sn bimetallic catalyst: synthesis of fully decorated furans and pyrroles
作者:Paresh Nath Chatterjee、Sujit Roy
DOI:10.1016/j.tet.2011.04.092
日期:2011.6
The heterobimetallic complex [Ir(COD)(SnCl3)Cl(μ-Cl)]2 catalyzes the direct substitution of hydroxyl groups in benzylic and propargylicalcohols by 1,3-dicarbonyl moiety. In 4-hydroxycoumarin, benzylation and propargylation occurs at the 3-position. Selective propargylation or allenylation takes place depending on the nature of propargylicalcohol. By applying the methodology, multi-substituted furans
Yb(OTf)3-catalyzed propargylation and allenylation of 1,3-dicarbonyl derivatives with propargylic alcohols: one-pot synthesis of multi-substituted furocoumarin
depending on the nature of propargylic alcohols. In addition, catalytic quantities of Yb(OTf)3 can also effectively promote the propargylation and allylation of 4-hydroxycoumarins at the 3-position. By applying this reaction as the key step, a multi-substituted furocoumarin can easily be synthesized in a one-pot procedure. The advantages of this method are broad scope, mild conditions, and easy handling