- Controlling multivalency and multimodality: Up to pentamodal dendritic platforms based on diethylenetriaminepentaacetic acid cores
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A highly versatile synthetic strategy is described to generate multimodal and multivalent platforms based on a diethylenetriaminepentaacetic (DTPA) core. Compounds with different functionalization patterns, from mono- to pentamodal, have been prepared using robust and simple chemistry.
- Pulido, Daniel,Albericio, Fernando,Royo, Miriam
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supporting information
p. 1318 - 1321
(2014/04/03)
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- Synthesis of O-benzyl hydroxamates employing the sulfonate esters of N-hydroxybenzotriazole
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The direct conversion of various carboxylic acids, that include sterically hindered amino acids and di-peptides, to O-benzyl hydroxamates is demonstrated using sulfonate esters of benzotriazoles under ambient and milder conditions without significant race
- Palakurthy, Nani Babu,Dev, Dharm,Paikaray, Sonali,Chaudhury, Susmitnarayan,Mandal, Bhubaneswar
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p. 7952 - 7958
(2014/02/14)
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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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