Boron sulfonic acid (BSA) catalyzed selective synthesis of aryl-bis(2-hydroxynaphth-1-yl)methanes and 14-alkyl- and 14-aryl-14H-dibenzoxanthenes under solvent-free condition

Abstract

This study investigated the selective synthesis of aryl-bis(2-hydroxy-1-naphthyl)methane for the first time under microwave irradiation in solvent-free medium within 5 min using 10 mol % of B(HSO4)3 (BSA) as reusable solid acid catalyst. The same reaction could also be conducted at 90-100 °C in neat for the formation of alkyl or aryl 14H-dibenzoxanthenes in presence of BSA catalyst with excellent yields.

Revisiting of Boron Sulfonic Acid Applications in Organic Synthesis: Mini-Review

“…Xanthene derivatives as main structural heterocycle have vast range of application from fluorescent materials and laser technologies to biological properties such as antiviral, antibacterial, antiflammatory agents [88][89][90][91]. BSA as a solid acid catalyst play an essential role in the reaction of 2naphthol (64) with aldehydes (4) due to 14-alkyl or aryl 14H-dibenzoxanthenes (65) synthesis which was reported by Borah and co-worker (Scheme 25) [92].…”

Synthesis of 14H-dibenzoxanthenes in green media using Sn(II)/nano silica as an efficient catalyst

“…The crucial ingredient of these reactions is a catalyst. Therefore, various homogeneous and heterogeneous catalysts have been developed for these reactions, including CuO nanoparticles ( Chaudhary et al, 2014 ), natural phosphates ( Fallah et al, 2017 ), magnetite nanoparticles ( Ghasemzadeh et al, 2013 ), ruthenium complexes ( Tabatabaeian et al, 2016 ), functionalized imidazolium salts ( Dutta et al, 2014 ), borane sulfonic acid ( Dutta and Borah, 2015 ), and cellulose sulfuric acid ( Azimi and Abbaspour-Gilandeh, 2016 ).…”