Hexahydrophthalic anhydride (HHPA) belongs to the family of acid anhydrides, the members of which are reactive organic chemicals of low molecular weight widely used in alkyd and epoxy resins. The major toxic effects ofthe acid anhydrides are mucosal and skin irritation and respiratory hypersensitivity, particularly asthma. Most of the reported cases of asthma caused by acid anhydrides were due ...

Carboxylic acid derivatives are the most widely occurring of all molecules, both in laboratory chemistry and in biological pathways. Specifically, acid derivatives are compounds in which the hydroxyl group of the carboxylic acid has been replaced by another acyl substituent that can act as a leaving group in nucleophilic acyl substitutions. These compounds can be acid halides, acid anhydrides, ...

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The synthesis of amide C N bonds through nucleophilic acyl substitutions constitutes one of the most fundamental transformations in chemical synthesis. Recently, the Staudingertype ligation of carboxylic acid derivatives (e.g., acid chlorides, anhydrides, acyl selenides, and thioesters) and azides has become a preeminent strategy for amide C N bond construction (Scheme 1a). However, the generat...

Aminoacyl adenylates (aa-AMPs) constitute essential intermediates of protein biosynthesis. Their polymerization in aqueous solution has often been claimed as a potential route to abiotic peptides in spite of a highly efficient CO2-promoted pathway of hydrolysis. Here we investigate the efficiency and relevance of this frequently overlooked pathway from model amino acid phosphate mixed anhydride...

Anhydrous sodium acetate will serve as the catalyst with maleic, chloro-maleic, and methylglutaconic anhydrides, giving yields of 0.54, 0.22, and 1.02 moles CO2 per mole of anhydride. The products of all these reactions are black and brown-black, are soluble in acetone, acetophenone, dioxane, and aqueous alkali and are insoluble in benzene, toluene, ether, chloroform and carbon tetrachloride, a...