Efficient Synthesis of 1,1'-(2,2-diphenylethene-1,1-diyl) Bis(1H-indole) by the Reaction of (2,2-difluoroethene-1,1-diyl) Dibenzene) with Indole Derivatives
DOI: https://doi.org/10.55373/mjchem.v28i1.355
Keywords: Boronic acid, catalysis, cross-coupling, iodoethnyl tosylate, gem-difluoroethene, palladium, indole.
Abstract
We report a convenient two-step methodology for the synthesis of 1,1'-(2,2-diphenylethene-1,1-diyl) bis(1H-indole). The cross-coupling reaction of 2,2-difluoro-1-iodoethenyl tosylate with 4 equiv of boronic acid in the presence of catalytic amounts of Pd(PPh3)2Cl2 and K3PO4 resulted in the formation of symmetrical di-coupling products ((2,2-difluoroethene-1,1-diyl) dibenzene) in high yields. The symmetrical products of the (diphenylethene-1,1-diyl) bis(1H-indole) were obtained in high yield by the reaction of the di-coupling product ((2,2-difluoroethene-1,1-diyl) dibenzene) with 2 equiv. of indole derivatives in the presence of base.