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

Abstract

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.

Chemistry of Pentafluorosulfanyl Derivatives and Related Analogs: From Synthesis to Applications

“…The overall procedure gives rise to SF 5 -cyclopropyl building blocks (Scheme 11, C). [56] Recent advances in pentafluorosulfanylation chemistry allowed to overcome some of the drawbacks encountered with SF 5 Cl synthesis and handling. Initially, Qing and co-workers reported a more accessible method for the synthesis of SF 5 Cl, relying on elemental sulfur, trichloroisocyanuric acid (TCICA) as the oxidative chlorinating agent and KF as the fluoride source (Scheme 12, A).…”

“…These transformations showcase once more the stability of the SF 5 group towards the abovementioned reaction conditions. [56]…”

Recent Advances in the Synthesis and Medicinal Chemistry of SF5 and SF4Cl Compounds

“…Figure 1 Examples of double substituted SF5 cyclopropanes 41 The C−Cl bond in the resulting adducts was then further functionalised through radical reductions or radical cyclizations to access a variety of SF5-cyclopropyl building blocks, such as the ones shown in Scheme 45.…”

Oxidative Fluorination of Heteroatoms Enabled by Trichloroisocyanuric Acid and Potassium Fluoride

“…Moreover, several transformations have been developed in the past few years with SF 5 Cl that may become even more accessible with this ability to synthesize the reagent easily in house. [67][68][69][70][71]…”

“…Between our discovery of a gas‐reagent‐free SF 5 Cl synthesis and Qing's optimization of the extraction procedure, exploring new applications in SF 5 radical chemistry and even designing/synthesizing new possible SF 5 transfer reagents now seem within reach. Moreover, several transformations have been developed in the past few years with SF 5 Cl that may become even more accessible with this ability to synthesize the reagent easily in house [67–71] …”