Metal-Free Cyclopropanol Ring-Opening C(sp³)–C(sp²) Cross-Couplings with Aryl Sulfoxides

Abstract

A metal-free method for formal β-arylation/ heteroarylation of ketones through efficient cyclopropanol ring-opening cross-couplings with aryl sulfoxides at room temperature has been developed. This protocol shows a broad substrate scope and promising scalability. In addition, the utility of the β-arylated ketones is further demonstrated through a variety of postcoupling transformations and synthetic applications.

Selective Carbon–Carbon Bond Cleavage of Cyclopropanols

“…The authors proposed that the reaction proceeds via an interrupted Pummerer reaction and subsequent [3,3]-sigmatropic rearrangement (Scheme 225). 454 Kurti and co-workers have very recently reported a related [3,3]-rearrangement of N-aryl Ocyclopropyl hydroxylamine derivatives. 455 Li and co-workers reported an elegant 6π-electrocyclic ring opening of a cyclopropyl alcohol intermediate to forge an aromatic ring in their synthesis of daphenylline (Scheme 226).…”

“…The authors proposed that the reaction proceeds via an interrupted Pummerer reaction and subsequent [3,3]-sigmatropic rearrangement (Scheme ). Kürti and co-workers have very recently reported a related [3,3]-rearrangement of N -aryl O-cyclopropyl hydroxylamine derivatives …”

Synthesis of γ‐Keto Sulfones through a Three‐Component Reaction of Cyclopropanols, DABCO ⋅ (SO2)2 and Alkyl Halides

“…In 2017, Kananovich and co‐workers reported the synthesis of γ‐keto sulfones via a copper‐catalyzed oxidative sulfonylation reaction of cyclopropanols (Scheme 1a) [6b] . Additionally, Huang and co‐workers discovered that cyclopropanols could act as nucleophiles to react with electrophilic sulfonium‐type intermediates leading to β‐arylated ketones [13] …”

Photocatalytic redox-neutral arylation of cyclopropanols with cyanoarenes via radical-mediated C–C and C–CN bond cleavage

“…2 The transition metal-catalyzed disconnection of the C–C bond of cyclopropanols under oxidative conditions affords metalated homoenolate intermediates, which can be further transformed into the corresponding β-arylated ketones with various aryl substrates, and this type of ring-opening of cyclopropanols is often based on the thermodynamic driving release of ring strain (Scheme 1A). 3 The arylation of cyclopropanols with heteroarenes via Minisci-type reactions is also well established using a photoredox catalyst or a stoichiometric oxidant. 4 The problems of two competing sites (C2 vs. C4) and/or overalkylation are always involved when a β-keto radical generated by the single-electron oxidative ring-opening of cyclopropanol undergoes addition to pyridines (Scheme 1B).…”