Diversity‐Oriented Desulfonylative Functionalization of Alkyl Allyl Sulfones

Xia, Yong; Studer, Armido

doi:10.1002/ange.201903668

Cited by 17 publications

(3 citation statements)

References 104 publications

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“…The reactive azide 10 can be readily prepared in situ and was successfully used by Renaud and us for radical azidation reactions before. [24][25][26] Under the above optimized conditions developed for the alkynylation process, the desired reaction proceeded smoothly to afford the rather unstable tertiary azide 11 in 70% isolated yield ( Figure 6). To further document the potential of the 1,3-alkene difunctionalization strategy, we investigated the photoredox-catalyzed three-component reaction of allylboronic ester 1a with various Michael acceptors as C-radical trapping reagents and the Langlois reagent (CF 3 SO 2 Na) as the trifluoromethyl radical source.…”

Section: Resultsmentioning

confidence: 99%

Radical 1,3-Difunctionalization of Allylboronic Esters with Concomitant 1,2-Boron Shift

Jana

Bhunia

Studer

2020

Chem

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Radical 1,3-trifluoromethylation/alkynylation of various allylboronic esters with concomitant 1,2-boron shift with alkynyl triflones is reported. These chain reactions proceed via CF 3-radical addition to the allylic double bond, and the adduct radical undergoes 1,2-boron migration to give a translocated C-radical that is trapped by the alkynyl triflone. As products, 1,2,3-trisubstituted alkanes with the trifluoromethyl group at position 1 and the alkynyl functionality at position 3 are formed. The valuable boron moiety is retained in the product and is rearranged to position 2. By using trifluoromethanesulfonyl azide as the radical trapping reagent, the cascade provides a 1-trifluoromethyl-3-azidyl-alk-2-ylboronic ester as the product and Michael acceptors as trapping reagents in combination with the Langlois reagent as the CF 3-radical precursor applying photoredox catalysis afford the corresponding 3-alkylated congeners in a three-component process. Further, the stereochemical course of the 1,2-boron migration and the trapping reaction are investigated.

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Section: Resultsmentioning

confidence: 99%

Radical 1,3-Difunctionalization of Allylboronic Esters with Concomitant 1,2-Boron Shift

Jana

Bhunia

Studer

2020

Chem

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“…Following the above protocol, a glucosyl group could be attached to the cysteine residue of this nonapeptide (23). Similarly, we showed Tyr-amyloid P component (27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38) amide could be glycosylated by our method with high e ciency (24). Amyloid b/A4 protein precursor 770 (135-155) is a cysteinecontaining peptide shown to play an important role in the neurodegeneration in Alzheimer's disease.…”

Section: Main Textmentioning

confidence: 74%

“…Homolyzation of the disul de bond 26 in 7 readily affords a thiyl radical 8. Reaction of 8 with the double bond in allyl glycosyl sulfone 1 leads to alkyl radical 2, which then would release [27][28] allyl sul de 3 and emit SO 2 to yield the key glycosyl radical 4. Trapping of the glycosyl radical 4 by disul de 7 regenerates the thiyl radical 8 and furnishes the desired S-glycoside 5.…”

Section: Main Textmentioning

confidence: 99%

Nonenzymatic StereoselectiveS-Glycosylation of Polypeptides and Proteins

et al. 2021

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Glycosylation (1-4) is an essential and powerful technique that Nature employs to regulate the properties and functions of proteins and polypeptides. Our capacity to emulate Nature's power, however, is limited by the methods available (5) to perform glycosylation on these complex biomolecules. So far, very few glycosylation reactions could operate under the conditions tolerated by biomolecules (e.g., aqueous media, mild pH, and ambient temperature), and the need to install glycosyl groups in a stereo-controlled fashion poses additional, signi cant challenges. Here we report a non-enzymatic glycosylation reaction that builds axial S-glycosidic bonds under biorelevant conditions. Our strategy exploits the exceptional functional group tolerance of radical processes, and is enabled by the design and use of allyl glycosyl sulfones as precursors to glycosyl radicals. Our method could introduce a variety of glycosyl units to the cysteine residues of polypeptides in a highly selective fashion. The power of this method is further demonstrated in the direct glycosylation of bioexpressed proteins. Computational and experimental studies provide insights into the reaction mechanism.

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Polarity Umpolung Strategy for the Radical Alkylation of Alkenes

Liu

et al. 2020

Angewandte Chemie

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Free radical mediated alkylation of alkenes is a challenging and largely unmet goal. Disclosed here is a conceptually novel “polarity umpolung” strategy for radical alkylation of alkenes using a portfolio of easily accessed, difunctional alkylating reagents. This strategy is achieved by substituting inherently nucleophilic alkyl radicals with electrophilic sulfone‐bearing surrogates, thus inverting the usual mode of reactivity. Along with alkylation, either an heteroaryl or oximino group is concurrently incorporated into the alkenes by a consecutive docking and migration process, leading to valuable products. The reaction displays a broad functional‐group tolerance under mild reaction conditions. The protocol opens new vistas for the late‐stage modification of complex natural products and drug molecules containing alkene moieties.

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Diversity‐Oriented Desulfonylative Functionalization of Alkyl Allyl Sulfones

Cited by 17 publications

References 104 publications

Radical 1,3-Difunctionalization of Allylboronic Esters with Concomitant 1,2-Boron Shift

Radical 1,3-Difunctionalization of Allylboronic Esters with Concomitant 1,2-Boron Shift

Nonenzymatic StereoselectiveS-Glycosylation of Polypeptides and Proteins

Polarity Umpolung Strategy for the Radical Alkylation of Alkenes

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