Reaction of N-alkylisoindoles with (bromoethynyl) triisopropylsilane afforded 1, 3-bis (triisopropylsilylethynyl) isoindoles in high yields. The formal C–H alkynylation proceeds under transition-metal-free conditions through [4+ 2] cycloaddition of the pyrrole ring of isoindole with bromoalkyne followed by ring-opening of the product.