Regio‐ and Stereoselective Thianthrenation of Olefins To Access Versatile Alkenyl Electrophiles

Chen, Junting; Li, Jiakun; Plutschack, Matthew B.; Berger, Florian; Ritter, Tobias

doi:10.1002/ange.201914215

Cited by 34 publications

(22 citation statements)

References 61 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In fact, only a few substituted alkenyl sulfonium salts have been successfully engaged in cross-couplings, 35 − 37 but no examples of vinylations have been reported. Our group recently reported the synthesis of alkenyl thianthrenium salts, 38 but a general reactivity profile in polar and cross-couling reactions has not been explored yet. Moreover, we were unsuccessful in engaging these salts in efficient couplings with aryl boronic acids via Suzuki-type reactions.…”

mentioning

confidence: 99%

Vinyl Thianthrenium Tetrafluoroborate: A Practical and Versatile Vinylating Reagent Made from Ethylene

et al. 2021

Self Cite

View full text Add to dashboard Cite

The use of vinyl electrophiles in synthesis has been hampered by the lack of access to a suitable reagent that is practical and of appropriate reactivity. In this work we introduce a vinyl thianthrenium salt as an effective vinylating reagent. The bench-stable, crystalline reagent can be readily prepared from ethylene gas at atmospheric pressure in one step and is broadly useful in the annulation chemistry of (hetero)cycles, N-vinylation of heterocyclic compounds, and palladium-catalyzed cross-coupling reactions. The structural features of the thianthrene core enable a distinct synthesis and reactivity profile, unprecedented for other vinyl sulfonium derivatives.

show abstract

mentioning

confidence: 99%

Vinyl Thianthrenium Tetrafluoroborate: A Practical and Versatile Vinylating Reagent Made from Ethylene

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…The thianthrenation reaction works on electron-rich systems such as carbocyclic arenes, some heterocyclic arenes, and olefins. [10][11][12][13][14][15][16][17] Arenes can be as electron rich as di-methoxybenzene or as electron poor as chlorobenzene, although for such electron-poor arenes the fluorinated thianthrene reagent (TFT) is required. The reaction tolerates many functional groups, such as amides, amines, alcohols, ethers, esters, and nitrogen heterocycles, and allows functionalization of even complex small molecules, such as the natural product strychnine or the pharmaceutical dasatinib.…”

Section: Account Synlettmentioning

confidence: 99%

“…The thianthrenyl group is an excellent leaving group and participates in palladium-catalyzed cross-coupling reactions, such as Suzuki couplings, Negishi couplings, Sonogahira couplings, Heck reactions, carbonylations, and sulfonylations (Scheme 4). 10,12,13 The reactivity of aryl thianthrenium salts in Suzuki coupling exceeds the reactivity of aryl bromides and aryl triflates, allowing brominated and triflylated arenes to be functionalized and cross-coupled via sulfonium salts while leaving other (pseudo)halides intact (Scheme 5). 10,13 Cross-coupling reactions that require more basic conditions, such as the Buchwald-Hartwig coupling, are more challenging to be adapted to thianthrenium salts because thianthrenium salts decompose with strong bases.…”

Section: Sulfonium Salts In Palladium-catalyzed Cross-couplingmentioning

confidence: 99%

Site-Selective Late-Stage C–H Functionalization via Thianthrenium Salts

Berger¹,

Ritter²

2021

Synlett

Self Cite

View full text Add to dashboard Cite

The high abundance of C–H bonds in organic molecules makes C–H functionalization a powerful approach to quickly increase the complexity of an organic molecule. However, the high abundance of C–H bonds also provides a challenge to C–H functionalization reactions: selectivity. While most C–H functionalization reactions produce mixtures of different products for most substrates, we have developed a highly selective method for aromatic C–H functionalization via sulfonium salts. The reaction does not require a certain directing group to be selective. The introduced functional group is a sulfonium group, which participates in various follow-up reactions such as palladium-catalyzed cross-coupling reactions and photoredox catalysis. Here we discuss our pathway to develop the reaction as well as its scope and utility.1 Introduction2 Site-Selective Synthesis of Sulfonium Salts3 Sulfonium Salts in Palladium-Catalyzed Cross-Coupling4 Sulfonium Salts in Photoredox Catalysis5 Sulfur(IV) Reductive Elimination6 Cine Substitution7 Conclusion

show abstract

“…[3] Nonetheless, the stereoselectivity challenge remains even for such metal-mediated coupling reactions, especially for tri-and tetrasubstituted olefins, because the problem of stereocontrol is relegated to the stereoselective synthesis of the required functionalized olefin precursors. [4,5] Thus, novel methods for the stereo-and regioselective synthesis of conjugated, highly substituted enynes are desirable. Herein, we report convenient access to 1,3-enynes from cis-olefins in a stereo-and regioselective manner through palladium-catalyzed alkenyl C À H functionalization that proceeds through putative exo-metallacycles as intermediates (Scheme 1).…”

mentioning

confidence: 99%

Palladium‐Catalyzed C−H Alkynylation of Unactivated Alkenes

2020

View full text Add to dashboard Cite

Palladium-catalyzed regio-and diastereoselective C À H functionalization with bromoalkynes and electronically unbiased olefins is reported. The picolinamide directing group enables the formation of putative 5 and 6-exo-metallacycles as intermediates to afford monoalkynylated products in up to 91 % yield in a stereospecific fashion. The systematic study reveals that substrates with a wide range of substituents on the olefin and bromoalkyne coupling partners are tolerated. Chemoselective transformations were demonstrated for the obtained amides, olefins, and alkynes. Conjugated 1,3-enynes are abundant in natural products, [*] B. Supporting information and the ORCID identification number for one of the authors of this article can be found under: https://doi.org/10.1002/anie.202000935. Scheme 2. Prior studies and challenges. TIPS = triisopropylsilyl. Angewandte Chemie Communications Scheme 5. Scope of alkynes. Yields and E/Z ratios are given of isolated products after purification. [a] Determined by 1 H NMR analysis of unpurified reaction mixture. [b] DCE used as solvent. [c] Thermal ellipsoids (100 K) shown at the 30 % probability level. Hydrogen atoms and disorder have been omitted for clarity. Boc = tert-butyloxycarbonyl, TBS = tert-butyldimethylsilyl. Scheme 6. Product derivatizations. TBAF = tetrabutylammonium fluoride. Angewandte Chemie Communications 7821

show abstract

Regio‐ and Stereoselective Thianthrenation of Olefins To Access Versatile Alkenyl Electrophiles

Cited by 34 publications

References 61 publications

Vinyl Thianthrenium Tetrafluoroborate: A Practical and Versatile Vinylating Reagent Made from Ethylene

Vinyl Thianthrenium Tetrafluoroborate: A Practical and Versatile Vinylating Reagent Made from Ethylene

Site-Selective Late-Stage C–H Functionalization via Thianthrenium Salts

Palladium‐Catalyzed C−H Alkynylation of Unactivated Alkenes

Contact Info

Product

Resources

About