Broad Scope Extra‐Annular [4 + 2] Cycloaddition of o‐Carboryne with Styrenes: Efficient Route to Carborane‐Fused Polycyclics

Abstract

Abstracto‐Carboryne (1,2‐dehydro‐o‐carborane) generated in situ from the precursor 1‐OTf‐2‐Li‐o‐1,2‐C2B10H10 undergoes an efficient extra‐annular [4 + 2] cycloaddition with styrenes at room temperature to give a series of carborane‐fused polycyclics in good to high isolated yields. This reaction is compatible with many functional groups and has a very broad substrate scope. Further transformations of the resultant products have been carried out, affording various multi‐functionalized o‐carboranes.