Rhodium(III)-CatalyzedOrthoHalogenations ofN-Acylsulfoximines and Synthetic Applications toward Functionalized Sulfoximine Derivatives

Abstract

Rhodium(III)-catalyzed ortho brominations and iodinations of N-acylsulfoximines by C-H bond activations have been developed. Subsequent product functionalizations involving cross-coupling reactions provide alkynylated sulfoximine derivatives and benzothiazines with wide potential for further synthetic applications.

A comprehensive overview of directing groups applied in metal-catalysed C–H functionalisation chemistry

“…In addition, still benefitting from efficient metallation of sulfoximine substrates in presence of RhCp*-catalysts, Bolm et al reported direct C–X coupling ( Scheme 168J ). 1046 Indeed, in presence of NIS or NBS as halogenating agents sulfoximes may be directly converted into ortho -halogenated congeners in high to excellent yield. This reaction allows therefore late-stage installation of amenable motifs for further diversifications.…”

Facile Preparation of Vinyl S‐Trifluoromethyl NH Aryl Sulfoximines

“…A rather low conversion was observed with formation of only the de‐iodo product 1′ accompanied by an insignificant quantity of the desired sulfoximine 4a . The reaction conditions described by Bolm et al for nonfluorinated sulfoximines were also considered and gave rise to a small amount of derivative 4a with a mixture of unidentified fluorinated products (Table , entry 2) . The conditions of Grela et al allowed the formation of target 4a in acceptable yield (45 %) in a mixture with the S ‐phenyl sulfoximine 1′ (Table , entry 3) .…”

Rhodium(III)‐Catalyzed C−H Alkynylation of N‐Methylsulfoximines

“…Along with the rapid expansion of transition‐metal‐catalyzed C−H activation in recent decades, direct C−H alkynylation reactions have recently been developed as a desirable method for facile synthesis of alkyne derivatives from C(sp 2 )−H and C(sp 3 )−H bonds . But till now, the only known method to make ortho ‐alkynylated sulfoximines is still normal Sonogashira‐type cross‐coupling from ortho ‐bromo or ‐iodo sulfoximines (Scheme a), where the requirement of preinstalling halogen atoms onto the arenes definitely caused some problems on atom‐ and step‐economy for the synthesis of target sulfoximines. Herein, we reported a rhodium(III)‐catalyzed direct alkynylation of ortho ‐C−H bonds on aryl sulfoximines, in which both diaryl and ( S , S )‐alkyl aryl sulfoximines are well compatible with this transformation (Scheme b).…”

“…In the past several decades, transition‐metal‐catalyzed direct functionalization of C−H bonds has emerged as an strategy for total synthesis of complex molecules and intermediates, which clearly demonstrates that the direct C−H functionalization stands out as the most straightforward strategy to synthesize functionalized sulfoximine. After the pioneering work on rhodium‐catalyzed oxidative annulation of sulfoximines and alkynes from Bolm and co‐workers, several groups have expanded the coupling partners of sulfoximines to diazo compounds, olefins,– pyridotriazoles, 3‐diazoindolin‐2‐imines, α‐MsO/TsO ketones, sulfoxonium ylides, etc . Furthermore, inspired by the well established Rh III catalytic system, several other transition‐metals, including Ru II , Cp*Co III , and Cp*Ir III , have been successfully applied to direct C−H functionalization of sulfoximines.…”