We have established that a cationic rhodium(I)-H8-BINAP complex catalyzes the complete intermolecular homo-[2+2+2] cycloaddition of aryl ethynyl ethers and cross-[2+2+2] cycloaddition of aryl ethynyl ethers with electron-deficient monoalkynes, leading to tri- and diaryloxybenzenes, respectively, at room temperature.