Tandem reactions using base-promoted processes have been developed for the synthesis of xanthone and chromone derivatives. The first examples of base-promoted insertion reactions of isolated carbon–carbon triple bonds into carbon–carbon σ-bonds have been reported. Using these approaches, polycyclic structures can be prepared. This reaction has the potential to become a general synthetic protocol for the preparation of multi-substituted xanthones and chromones due to the abundance of easily accessible starting materials possessing diverse substituent groups.

A highly efficient palladium-catalyzed cascade reaction of propargyl carboxylates bearing a furanyl group with organoborons was developed. This methodology offers rapid access to polycyclic Diels–Alder cycloadducts in good to high yields. The thus-formed oxygen-bridged products were further converted into anthracene derivatives in a chemoselective manner under mild conditions.

An efficient acid-catalyzed approach to the synthesis of functional 1,4-dihydropyridines from the reaction of readily available enaminones with aldehydes has been developed. This methodology was realized by a cascade reaction involving first formation of divinylmethanes and subsequent intramolecular cyclization.

An efficient, regioselective, iron-catalyzed intramolecular hydroaryloxylation of 2-propargylphenols or naphthols is reported. The reactions proceed through an endo-dig cyclization to afford benzopyran or naphthopyran derivatives in good to high yields using iron(III) chloride as the catalyst with the assistance of aniline in dimethylformamide (DMF).