Vinylation sulfonic acid amides

There have been two general approaches to the direct asymmetric epoxidation of carbonyl-containing compounds (Scheme 1.2) ylide-mediated epoxidation for the construction of aryl and vinyl epoxides, and a-halo enolate epoxidation (Darzens reaction) for the construction of epoxy esters, acids, amides, and sulfones. 

Carboxymethylcellulose, polyethylene glycol Combination of a cellulose ether with clay Amide-modified carboxyl-containing polysaccharide Sodium aluminate and magnesium oxide Thermally stable hydroxyethylcellulose 30% ammonium or sodium thiosulfate and 20% hydroxyethylcellulose (HEC) Acrylic acid copolymer and oxyalkylene with hydrophobic group Copolymers acrylamide-acrylate and vinyl sulfonate-vinylamide Cationic polygalactomannans and anionic xanthan gum Copolymer from vinyl urethanes and acrylic acid or alkyl acrylates 2-Nitroalkyl ether-modified starch Polymer of glucuronic acid... 

Peptide thioesters (Section 15.1.10) are generally prepared by coupling protected amino acids or peptides with thiols and are used for enzymatic hydrolysis. Peptide dithioesters, used to study the structures of endothiopeptides (Section 15.1.11), may be prepared by the reaction of peptide nitriles with thiols followed by thiolysis (Pinner reaction). Peptide vinyl sulfones (Section 15.1.12), inhibitors of various cysteine proteases, are prepared from N-protected C-terminal aldehydes with sulfonylphosphonates. Peptide nitriles (Section 15.1.13) prepared by dehydration of peptide amides, acylation of a-amino nitriles, or the reaction of Mannich adducts with alkali cyanides, are relatively weak inhibitors of serine proteases. 

Horner-Emmons reaction of N-terminal blocked aldehyde 1 with sulfonylphosphonates in the presence of sodium hydride gives the amino acid vinyl sulfone 2, which is deprotected with acid and converted into its chloride or tosylate salt 3 and coupled by the mixed anhydride method with an N-terminal protected peptide or amino acid to give the desired peptide vinyl sulfones 4 (Scheme 2). 4 5 N-Terminal protected aldehydes 1 are obtained from reduction of Boc amino acid V-methoxy-A-methylamides (Weinreb amides, see Section 15.1.1) by lithium aluminum hydride. 9 The V-methoxy-V-methylamide derivatives are prepared by reaction of Boc amino acids with N,O-dimethylhydroxylamine hydrochloride in... 

ANILINE-4-SULFONIC ACID (121-57-3) Decomposes on contact with strong acids, forming sulfur trioxide. Aqueous solution is acidic violent reaction with strong bases. Incompatible with alkylene oxides, aliphatic amines, alkanolamines, amides, ammonia, epichlorohydrin, organic anhydrides, isocyanates, oxidizers, vinyl acetate. 

Sulfonic acid vinyl amides 1 -Sulfonyl-1 -isonitriles 2-Sulfonylvinylamines Thiolcarbalkoxyisocyanates... 

Sulfonic acid a-alkoxyalkyl amides from vinyl ethers... 

Electron irradiation 2-Sulfonylvinylamines from sulfonic acid vinyl amides s. U, 646 ... 

Thioethers (sulfides)319 can be converted to their a-carbanion derivative (296, M = Li, Na, K) by treatment with strong bases such as -butyllithium, sodium amide (NaNH2) or potassium amide (KNH2). The hydrogen atom a-to the sulfur atom of sulfides is a weaker acid than that a-to a carbonyl, nitrile or nitro group and stronger bases are required for deprotonation. Sulfides are stronger acids, than the allylic, vinyl, and aromatic hydrocarbons discussed above, however. The various oxides of sulfur can also be converted to a-carbanions. The most important derivatives are the a-carbanions derived from sulfoxides (297). sulfones (298), and... 

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