Design and synthesis of C3-symmetric molecules containing oxepine and benzofuran moieties via Metathesis

Abstract

• We demonstrated a simple synthetic strategy to assemble C 3 -symmetric star-shaped phenyl and triazine central core based oxepine and benzofuran derivatives. • The key steps involved are Claisen rearrangement, double-bond isomerization and cyclo-trimerization. • We introduced oxepine and furan ring systems in C 3 -symmetric star-shaped phenyl and triazine core derivatives using olefin metathesis. • We studied photophysical properties of prepared molecules by fluorescence spectroscopic data. We report a new synthetic strategy to C 3 -symmetric star-shaped phenyl and triazine central cores bearing oxepine and benzofuran ring systems. In this regard, we have explored the application of metathetic strategy to construct C 3 -symmetric molecules starting with commercially available p -hydroxy acetophenone and p -hydroxy benzonitrile through cyclotrimerization, double bond isomerization, and ring-closing metathesis as key steps. We also studied photophysical properties of these molecules by fluorescence spectroscopic data. All compounds except 1 and 2 exhibit strong fluorescence.