- A Route to O-Aminosulfonates and Sulfonamides through Insertion of Sulfur Dioxide and Hydrogen Atom Transfer
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A three-component reaction of aryldiazonium tetrafluoroborates, the 1,4-diazabicyclo[2.2.2]octane?bis(sulfur dioxide) adduct [DABCO?(SO2)2] and hydroxylamines under catalyst-free and additive-free conditions has been developed, providing aryl O-aminosulfonates in good yields. Sulfonamides could also be obtained via a one-pot process through the reaction of aryldiazonium tetrafluoroborates, DABCO?(SO2)2 and amines in the presence of N-hydroxybenzotriazole. A mechanism involving the insertion of sulfur dioxide and hydrogen atom transfer is proposed and supported by theoretical calculations. (Figure presented.).
- Liu, Tong,Zheng, Danqing,Li, Zhenhua,Wu, Jie
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supporting information
p. 2653 - 2659
(2017/08/16)
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- Sulfonamide synthesis using N-hydroxybenzotriazole sulfonate: An alternative to pentafluorophenyl (PFP) and trichlorophenyl (TCP) esters of sulfonic acids
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The N-hydroxybenzotriazole (HOBt) sulfonate esters undergo amidation under ambient conditions in the presence of di-isopropylethyl amine. This method can be applied to varieties of amines including sterically hindered amino acid esters in less time with reasonably good yields. HOBt ester of sulfonic acids can be a replacement for pentafluorophenyl and trichlorophenyl ester as well as chloride moiety of sulfonyl chloride for amidation.
- Palakurthy, Nani Babu,Mandal, Bhubaneswar
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scheme or table
p. 7132 - 7134
(2012/02/01)
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- Organophosphorus and Nitro-Substituted Sulfonate Esters of 1-Hydroxy-7-azabenzotriazole as Highly Efficient Fast-Acting Peptide Coupling Reagents
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Organophosphorus esters 9, 10, 14, and 15 prepared via reaction of diethyl- and diphenylphosphoryl chloride, di(o-tolyl)phosphinyl chloride, and 2,8-dimethylphenoxaphosphinyl chloride with HOAt are excellent coupling reagents for peptide synthesis which are generally superior to their uronium/guanidinium analogues and HOBt- or HODhbt-derived phosphate ester counterparts in minimizing loss of configuration during segment coupling. The phosphinyl analogues are more shelf-stable than the phosphoryl systems. The new reagents have been tested in segment couplings leading to two tripeptides (20, 21) and a hexapeptide 22. Outstanding utility is also shown for the solid-phase assembly of the ACP decapeptide. Similar results were obtained with the 2- and 4-nitro- and 2,4-dinitrophenylsulfonyl esters derived from HOAt.
- Carpino, Louis A.,Xia, Jusong,Zhang, Chongwu,El-Faham, Ayman
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- Sulfonic acid esters
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A novel process for the amidation or esterification which comprises reacting a compound having a carboxy group with a compound having an amino or imino group which can be acylated or with a compound having a hydroxy group in the presence of a sulfonic acid ester of the formula: wherein R1 is an organic group and R2 O-- is a residue of a strongly acidic N-hydroxy compound as a condensation agent, and a novel sulfonic acid ester useful as such a condensation agent and a process for the preparation thereof.
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