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The catalytic reactions of indoles with CO2and phenylsilane afforded indolo[3,2-b]carbazoles, where the fused benzene ring was constructed by forming two C–H bonds and four C–C bonds with two CO2molecules via deoxygenative conversions. Nine-membered cyclophanes made up of three indoles and three CO2molecules were also obtained, where the cyclophane framework was constructed by forming six C–H bonds and six C–C bonds. These multicomponent cascade reactions giving completely different carbocycles were switched simply by choosing the solvent, acetonitrile or ethyl acetate.

A series of axially chiral peri-xanthenoxanthenes (PXXs) were synthesized from 1,1′-bi-2-naphthol without optical resolution. These are the first examples of chiral PXXs. Among them, PXX 5with two naphthalene rings connected via a methylenedioxy bridge and a chiral axis displayed intense fluorescence (FL) and circularly polarized luminescence (CPL) both in solution (ΦFLof 0.72 and |glum| of 1.4 × 10–3) and in the solid state (ΦFLof 0.13 and |glum| of 4.8 × 10–3). The bridged structure of PXX 5adjusts the angle between the vectors of the electric and magnetic transition dipole moments, which is essential for showing intense CPL activity.