Solvent interception, heterocyclization and desilylation upon NBS-induced sulfamidation of trimethyl(vinyl)silane

Allyl halides with triflamide under oxidative conditions form halogen-substituted amidines. Allyl cyanide reacts with triflamide in acetonitrile or THF solutions in the presence of NBS to give the products of bromotriflamidation with a solvent interception, whereas in CH2Cl2 two regioisomers of the bromotriflamidation product without a solvent interception were obtained. The formed products undergo base-induced dehydrobromination to give linear isomers with the new C=C bond conjugated either with the nitrile group or the amidine moiety or alkoxy group. Under the same conditions, the reaction of allyl alcohol with triflamide gives rise to amidine, which was prepared earlier by the reaction of diallyl formal with triflamide. Unlike their iodo-substituted analogs, bromo-substituted amidines successfully transform into imidazolidines under the action of potassium carbonate.

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“…The reason for this behavior is that triflamide practically does not react with unsaturated substrates in solvents of low basicity [ 20 ].…”

Section: Resultsmentioning

confidence: 99%

Triflamidation of Allyl-Containing Substances:Unusual Dehydrobromination vs. Intramolecular Heterocyclization

et al. 2022

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“…In view of numerous examples illustrating specific behavior of triflamide, distinct from that of non-fluorinated sulfonamides [ 58 , 60 , 70 , 71 ], it was of interest to compare the relative iodinating activity of different N -iodinated sulfonamides. We performed such an analysis at the MP2//B3LYP level of theory using as a criterion the ease of the N–I bond rupture in both active intermediates capable of acting as iodinating agents, namely, RSO 2 NHI ( 7 ) and RSO 2 NI 2 ( 8 ).…”

Section: Resultsmentioning

confidence: 99%

Trifluoromethanesulfonamide vs. Non-Fluorinated Sulfonamides in Oxidative Sulfamidation of the C=C Bond: An In Silico Study

2020

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A theoretical analysis of the reaction of oxidative sulfamidation of several alkenes was performed in order to explain the various experimental observations and different reactivity of triflamide and non-fluorinated sulfonamides. Transformations occurring in the system alkene–sulfonamide in the presence of oxidative system (ButOCl + NaI) were analyzed at the MP2/DGDZVP//B3LYP/DGDZVP level of theory using the IEF-PCM method for taking into account the solvent acetonitrile (MeCN) effect. As the model substrates, styrene, trimethyl(vinyl)silane, dimethyl(divinyl)silane and diphenyl(divinyl)silane were chosen and mesylamide, triflamide, tosylamide and p-nosylamide were taken as the reagents. ButOI generated from ButOCl and NaI reacts with sulfonamides to give N-iodinated sulfonamides RSO2NHI and RSO2NI2 as active intermediates, the iodinating activity of the latter being notably higher. The analysis allowed to answer such challenging questions as different reactivity of nonfluorinated sulfonamides leading to aziridination and of triflamide resulting in the formation the main products of bis-triflamidation, or different regioselectivity of halogenation of styrene and trimethyl(vinyl)silane caused by a linear intermediate iodonium cation in the former case and a cyclic one in the latter.

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“…In another recently developed route, the imidazoline ring was constructed through the one-pot reaction of triflamide with silane in acetonitrile containing N -bromosuccinimide accompanied by the dehydrobromination of amidine with the aid of potassium carbonate. 134 One of the most challenging topics in the field of organic synthesis is related to developing novel strategies of regio- and stereoselective approaches to obtain vicinal diamines. 135–139 Timmons et al 140 developed an approach for the direct amination of enones, which is regio-, stereo-, and chemoselective deamination of enones employing electrophiles such as N -chlorosuccinimide and tosyl amine.…”

Section: Synthetic Approachesmentioning

confidence: 99%

Recent progress in the chemistry of β-aminoketones

Hammouda

Elattar

2022

RSC Adv.

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Solvent interception, heterocyclization and desilylation upon NBS-induced sulfamidation of trimethyl(vinyl)silane

Abstract: NBS-induced oxidative sulfamidation of trimethyl(vinyl)silane is strongly solvent and reagent dependent leading to various heterocycles in up to quantitative yield.

Cited by 24 publications

References 43 publications

Triflamidation of Allyl-Containing Substances:Unusual Dehydrobromination vs. Intramolecular Heterocyclization

Triflamidation of Allyl-Containing Substances:Unusual Dehydrobromination vs. Intramolecular Heterocyclization

Trifluoromethanesulfonamide vs. Non-Fluorinated Sulfonamides in Oxidative Sulfamidation of the C=C Bond: An In Silico Study

Recent progress in the chemistry of β-aminoketones

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