Synthesis of cyclobutane-fused dihydroazepines via rhodium-catalyzed intramolecular [4 + 3] cycloaddition of 1-sulfonyl-1,2,3-triazoles

We report a rhodium-catalyzed intramolecular [4 + 3] cycloaddition of 1-sulfonyl-1,2,3-triazoles that enables the efficient synthesis of cyclobutane-fused dihydroazepines in moderate to good yields. Meanwhile, three stereo centers were constructed, and one single diastereomer was obtained in each case. The stereoselectivity control was also discussed.