Investigation into the Organobismuth Dismutation and Its Use for Rational Synthesis of Heteroleptic Triarylbismuthanes, Ar12Ar2Bi

Organobismuthanes undergo dismutation, a substituent scrambling process, complicating the synthesis of unsymmetrically trisubstituted bismuthanes of the general formula Ar12Ar2Bi. Although the dismutation is a mechanistically diverse phenomenon, at ambient or lower temperatures, dismutation is triggered mainly by an electrophilic bismuth source. Therefore, the selection of the electrophile, Ar12BiX (X = tosylate or iodide if Ar1 = mesityl) or Ar1BiX2 (X = tosylate), and its use in low concentration during the reaction is key to suppressing the dismutation, leading to new, streamlined protocols utilizing direct arylations of Ar12BiX (X = OTs or I) or Ar1Bi­(OTs)2 with organozincs affording heteroleptic triarylbismuthanes Ar12Ar2Bi.