Direct halosulfonylation of alkynes: an overview

Zhang, Yujun; Vessally, Esmail

doi:10.1039/d1ra03443j

Cited by 27 publications

(19 citation statements)

References 68 publications

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“…4 and 8 ). According to our observations, the reaction speed and conversion is greatly enhanced by irradiation with visible light; an added advantage is that the reaction also gives a higher final conversion in a shorter reaction time 55 , 60 – 64 . Additionally, reaction time monitoring, solvent molarity, and the use of freshly prepared sulfonyl iodide are vital to inhibit compound 4 formation in this rapid transformation.…”

Section: Resultsmentioning

confidence: 63%

“…Based on the results of the above control experiment, previous 1 – 11 , 37 – 40 , 47 , 54 – 64 , 69 , 70 reports and our own research experience 41 , a plausible mechanism is depicted in Fig. 9 for compounds 3 ′, 51 and 76 (Supplementary Fig.…”

Section: Resultsmentioning

confidence: 83%

“…However, 4-toluenesulfonyl chloride ( S17 ) failed to give the desired product under optimized reaction conditions. The reason for the low reactivity of the sulfonyl bromides/chlorides is due to the relative strength of the sulfone–halogen bond 54 – 64 . The UV–vis absorption spectra of sulfonyl iodide 2a in various solvents (DCM, MeCN, and THF in 10 −2 –10 −5 M) were measured (Supplementary Figs.…”

Section: Resultsmentioning

confidence: 99%

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Photoinduced ynamide structural reshuffling and functionalization

Mutra

Wang

2022

Nat Commun

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The radical chemistry of ynamides has recently drawn the attention of synthetic organic chemists to the construction of various N-heterocyclic compounds. Nevertheless, the ynamide-radical chemistry remains a long-standing challenge for chemists due to its high reactivity, undesirable byproducts, severe inherent regio- and chemoselective problems. Importantly, the ynamide C(sp)-N bond fission remains an unsolved challenge. In this paper, we observe Photoinduced radical trigger regio- and chemoselective ynamide bond fission, structural reshuffling and functionalization of 2-alkynyl-ynamides to prepare synthetically inaccessible/challenging chalcogen-substituted indole derivatives with excellent step/atom economy. The key breakthroughs of this work includes, ynamide bond cleavage, divergent radical precursors, broad scope, easy to handle, larger-scale reactions, generation of multiple bonds (N-C(sp2), C(sp2)-C(sp2), C(sp2)-SO2R/C-SR, and C-I/C-Se/C-H) in a few minutes without photocatalysts, metals, oxidants, additives. Control experiments and 13C-labeling experiments supporting the conclusion that sulfone radicals contribute to ynamide structural reshuffling processes via a radical pathway.

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Section: Resultsmentioning

confidence: 63%

Section: Resultsmentioning

confidence: 83%

Section: Resultsmentioning

confidence: 99%

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Photoinduced ynamide structural reshuffling and functionalization

Mutra

Wang

2022

Nat Commun

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“…Iodosulfonylation of 10 with I 2 /TsNa/DTBP (di‐ tert ‐butyl peroxide) at 60 °C (entry 5) [45] or by a modification, wherein TsNa was replaced by TsNHNH 2 , were unsuccessful to yield 13 b (entry 6). Subjecting 10 to the recently reported protocol of iodosulfonylation of aryl alkynes [46,47] with TsNHNH 2 /KI/(BzO) 2 at rt did produce the expected ( E )‐ β ‐iodovinylsulfone of 2′‐deoxyguanosine 13 b (60%; entry 7). Desilylation of 13 b with NH 4 F/AcOH in MeOH (60 °C/3 h) provided 14 (70%).…”

Section: Resultsmentioning

confidence: 99%

Purine Nucleosides with a Reactive (β‐Iodovinyl)sulfone or a (β‐Keto)sulfone Group at the C8 Position and Their Polymerase‐Catalyzed Incorporation into DNA

et al. 2022

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Iodosulfonylation of an ethynyl group attached at C8‐position of 2′‐deoxyadenosine or 2′‐deoxyguanosine A with TsNa or TsNHNH2, as tosyl source, and I2 or KI, as iodide source, provided 8‐(1‐iodo‐2‐tosylvinyl) nucleosides B with (β‐iodovinyl)sulfone group tethered to C8 position of the purine ring. Treatment of B with ammonia followed by acid‐catalyzed hydrolysis of the intermediary β‐sulfonylvinylamines C gave 8‐(β‐keto)sulfones D. The iodovinylsulfone probes B undergo nucleophilic substitution of iodide with thiols or amines, via an addition‐elimination path, to provide vinyl thioethers or vinyl amines, respectively. The 8‐(β‐keto)sulfone probes D react with electrophiles such as alkyl bromides resulting in α‐alkylation. The 5′‐triphosphate of 2′‐deoxyadenosine analog of D was incorporated by a human DNA polymerase into a double‐stranded DNA oligonucleotide possessing a one‐nucleotide gap substrate.

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“…This would allow for the preparation of the desired product 2 . Initially (Scheme 1d), only multisubstituted α,β-enones 4 were obtained via halosulfonylation; 10–12 however, to our delight, when the sulfonylhydrazide was removed, halocyclization 13,14 was observed, affording the pyrimidobenzothiazole 3a in 92% yield. Based on this result, we conducted the reaction in the absence of TBHP which resulted in a decrease in the yield of the desired product.…”

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confidence: 98%