Synthetic Route to Benzostannoles via Al−Li‐dimetal Intermediate and Their Application to Dibenzofulvene Synthesis

Abstract

Benzostannoles were synthesized from commercially available and easily accessible substrates. The ring construction proceeds via an Al‐Li‐dimetal intermediate generated in situ from 1‐bromo‐2‐(silylethynyl)benzenes. This methodology provided various 2‐silylbenzostannoles in good yields. The benzostannoles obtained were converted into dibenzofulvenes by treatment with 1,2‐dibromobenzenes in the presence of a Pd catalyst. This transformation yielded various types of symmetrical and unsymmetrical dibenzofulvenes, with combination of the benzostannoles and 1,2‐dibromobenzenes.