Radical Addition of SF5Cl to Cyclopropenes: Synthesis of (Pentafluorosulfanyl)cyclopropanes

With the goal of accessing yet unknown SF5-cyclopropyl building blocks, the radical addition of SF5Cl to cyclopropenes was investigated. Addition of the SF5 radical occurs regioselectively at the less substituted carbon of cyclopropenes and trans to the most hindered substituent at C3, while chlorine atom transfer proceeds with moderate to high levels of diastereocontrol. The carbon–chlorine bond in the resulting adducts can undergo subsequent radical reduction or be involved in a radical cyclization.