3-Zinciobenzofuran and 3-zincioindole: Versatile tools for the construction of conjugated structures containing multiple benzoheterole units
(Chemical Equation Presented) Closing the ring: Thermally stable but reactive 3-zinciobenzofurans and indoles were synthesized by metalative cyclization of 2-ynyl phenols or anilines. Furthermore, a variety of extended π-conjugated molecules were obtained by Pd-catalyzed cross-coupling reactions of these heterocycles with mono- or polyhalo-substituted arenes and alkenes (R2Haln; see scheme; Bn = benzyl).