Cerium(iii)-catalyzed regioselective coupling of 2-hydroxychalcones and polyphenols: an efficient domino approach towards synthesis of novel dibenzo-2,8-dioxabicyclo[3.3.1]nonanes†
Abstract
Efficient one-pot construction of functionalized dibenzannulated bicyclic-O,O-ketals is accomplished by CeCl3·7H2O–NaI (5 mol% each) catalyzed coupling of 2-hydroxychalcones with resorcinol/phloroglucinol via regioselective Michael addition–bicyclization cascade. The enhanced nucleophilicity driven reaction of phloroglucinol with two chalcone partners delivered facile access to unprecedented novel bisbicyclic-O,O-ketals. Installation of hydrogen donor phenolic function in the conformationally constrained bicyclic-O,O-ketal core make the designed targets potential anticoagulant candidates.