A new method to prepare 3,3-disubstituted phthalides [isobenzofuran-1(3H)-ones] from alpha-substituted 2-bromostyrenes has been developed. The reaction of alpha-substituted 2-lithiostyrenes, generated in situ by bromine-lithium exchange between alpha-substituted 2-bromostyrenes and butyllithium, with carbon dioxide gave the corresponding lithium 2-vinylbenzoates, which upon treatment with concentrated hydrochloric acid afforded the desired products in one pot.
Domino One-Pot Process for the Synthesis of Isobenzofuran-1(3<i>H</i>)-ones via [Cu]-Catalysis Using Water as the Green Solvent
作者:Lodi Mahendar、Gedu Satyanarayana
DOI:10.1021/acs.joc.5b00888
日期:2015.7.17
An efficient domino one-pot strategy via [Cu]-catalyzed intermolecular "cyanation" of o-bromobenzyl alcohols -> in situ intramolecular "nudeophilic attack" -> "hydrolysis" is presented, for the synthesis of isobenzofuran-1(3H)-ones. Significantly, the reaction is successfully carried out under environmentally benign conditions, using water as sole green solvent.