4,5-Disubstituted pyrenes from phenangermoles

Abstract

Herein, we report a new method for the synthesis of 4,5-disubstitued pyrene from phenangermoles via a Pd-catalyzed annulative π-extension reaction. In particular, discriminated 4- and 5-position-substituted pyrene derivatives were achieved in this work. The method established here not only displays obvious selectivity between phenangermoles and dibenzosiloles, but also distinguishes the reactivity of phenangermoles from phenansiloles. The successful transformation of arylalkylacetylenes under standard conditions has not been reported thus far. The surprising compatibility of propargyl bromide allows the product to contain the benzyl bromide group, which provides a convenient route for further derivatization.