Arylation and Heteroarylation of the Phosphole Ring

Article abstract of DOI:10.1021/jo00295a046

In the presence of AlCl3, the dienic system of a phosphole P-W(CO)5 complex can serve to alkylate electron-rich arenes such as anisole or heteroarenes such as furan and thiophene.The 2-aryl-2,5-dihydrophosphole complexes thus obtained can be converted into the corresponding 2-arylphospholes via decomplexation, reduction, bromination, and dehydrobromination.The overall yields are satisfactory.The thiophene ring can serve as a functionalizable carrier for the phosphole ring.Thus, a 2-(2-thienyl)phosphole P-W(CO)5 complex can be easily acetylated or formylated on the C5 position of the thiophene ring by CH3C(O)Cl + AlCl3 or HC(O)N(Me)Ph + POCl3, respectively.