A solid complex, readily prepared from commercially available sodium triphenylphosphine-m-sulfonate (TPPMS) and carbon tetrabromide, can be used as an easily recoverable and reusable catalyst system for one-pot condensation of 2-naphthol with aldehydes to construct 14-aryl(alkyl)-14H-dibenzo[a,j]xanthene derivatives and one-pot condensation of 2-naphthol with aldehydes and cyclic 1,3-dicarbonyl compounds to construct 12-aryl(alkyl)-8,9,10,12-tetrahydrobenzo[a]xanthen-11-one derivatives.An easily recoverable and reusable catalyst system was developed to construct 14-aryl(alkyl)-14H-dibenzo[a,j]xanthene derivatives and 12-aryl(alkyl)-8,9,10,12-tetrahydrobenzo[a]xanthen-11-one derivatives.

Commercially available stable radical cation triarylaminium salt can be used as an efficient initiator for Friedel–Crafts reaction of indoles with enamides to regioselectively construct complex indole derivatives and for double Friedel–Crafts reaction of indoles with vinyl ethers to offer 3,3′-Bis(indolyl)alkane derivatives. The ready availability of the starting materials and the usefulness of the products make this strategy attractive.