BiX-Mediated Hydrohalogenations of HDDA Benzynes: An Approach to Polycyclic Aryl Halides.

Here we demonstrate the hydrohalogenation reactions of HDDA benzynes promoted by BiX reagents for the generation of complex aryl halides. All three bismuth(III) halides can act as the source for their respective halides, i.e., Cl or Br or I. The regiochemical preference for hydrohalogenation is dependent on the nature of the substituent present at the diyne terminus but neither on the linker nor on the BiX reagent. The substrate scope for this transformation is broad in terms of the tethers A-B-C and the substituents R and R.