Reaction of o-azidobenzenesulfonamides with ethyl carbonochloridate afforded the corresponding amide derivatives, which gave 3-ethoxy-1,2,4-benzothiadiazine 1,1-dioxides through an intramolecular aza-Wittig reaction. The reaction was found to be general through the synthesis of a number of benzothiadiazine 1,1-dioxides. Acid-catalyzed hydrolysis of 3-ethoxy-1,2,4-benzothiadiazine 1,1-dioxides f...

The Staudinger ligation provides a means to form an amide bond between a phosphinothioester and azide. This reaction holds promise for the ligation of peptides en route to the total chemical synthesis of proteins. (Diphenylphosphino)methanethiol is the most efficacious of known reagents for mediating the Staudinger ligation of peptides, providing high (> 90%) isolated yields for equimolar coupl...

The traceless Staudinger ligation enables the formation of an amide bond between a phosphinothioester (or phosphinoester) and an azide without the incorporation of residual atoms. Here, the coupling of peptides by this reaction was characterized in detail. Experiments with [(18)O]H(2)O indicated that the reaction mediated by (diphenylphosphino)methanethiol proceeded by S-->N acyl transfer of th...

Reactions of N-isocyaniminotriphenylphosphorane with cyclopentanone have been studied in the presence of aromatic carboxylic acids and primary amines, proceeds smoothly at room temperature under neutral conditions to afford sterically congested 1,3,4-oxadiazole derivatives by an intramolecular Aza-Wittig cyclization in CH2Cl2 in excellent yields. The structures of the products were deduced from...

The anionic [2,3] sigmatropic Wittig rearrangements of deprotonated 4-hetera-1-pentenes and the anionic [3,3] sigmatropic Cope rearrangements of 3-substituted-1,5-hexadienes were explored by using density functional theory calculations. While the deprotonated anionic 3-hydroxy-1,5 hexadiene (2a), 3-thiohydroxy-1,5-hexadiene (2c), and 3-formamidyl-1,5-hexadiene (2d) Cope substrates undergo conce...

reactions of n-isocyaniminotriphenylphosphorane with cyclopentanone have been studied in the presence of aromatic carboxylic acids and primary amines, proceeds smoothly at room temperature under neutral conditions to afford sterically congested 1,3,4-oxadiazole derivatives by an intramolecular aza-wittig cyclization in ch2cl2 in excellent yields. the structures of the products were deduced from...

2-Imidazolines and imidazoles have been accessed by an aza-Wittig sequence featuring novel N-acylation methodology for sulfonamides and optimized conditions for ring closure.

Since the discovery of organic azides by Peter Griess more than 140 years ago, numerous syntheses of these energy-rich molecules have been developed. In more recent times in particular, completely new perspectives have been developed for their use in peptide chemistry, combinatorial chemistry, and heterocyclic synthesis. Organic azides have assumed an important position at the interface between...