Transition metal-free direct trifluoromethylthiolation of indoles using trifluoromethanesulfonyl chloride in the presence of triphenylphosphine

Abstract

A novel triphenylphosphine-mediated direct trifluoromethylthiolation of indole derivatives using trifluoromethanesulfonyl chloride as the SCF₃ source was developed. Sodium iodide facilitated this transformation by generating iodine in situ which was found to accelerate this transformation. The use of a transition metal-free protocol, readily available reagents, and mild reaction conditions allowed this protocol to be easily scaled up.