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 chemistry, biology, medicine, and materials science. In this Review, the fundamental characteristics of azide chemistry and current developments are presented. The focus will be placed on cycloadditions (Huisgen reaction), aza ylide chemistry, and the synthesis of heterocycles. Further reactions such as the aza-Wittig reaction, the Sundberg rearrangement, the Staudinger ligation, the Boyer and Boyer-Aube rearrangements, the Curtius rearrangement, the Schmidt rearrangement, and the Hemetsberger rearrangement bear witness to the versatility of modern azide chemistry.

Organic Azides: An Exploding Diversity of a Unique Class of Compounds

Seit der Entdeckung der organischen Azide vor uber einhundertvierzig Jahren durch Peter Gries wurde eine Reihe von Synthesen fur diese energiereichen Molekule entwickelt. In letzter Zeit haben sich vollig neue Perspektiven durch Anwendungen in der Peptidchemie, der kombinatorischen Chemie und der Heterocyclensynthese ergeben. Auf dem interdisziplinaren Gebiet zwischen Chemie, Biologie, Medizin und Materialwissenschaften nehmen organische Azide inzwischen einen wichtigen Raum ein. In diesem Aufsatz werden die Grundzuge der Azid-Chemie dargelegt und aktuelle Entwicklungen auf diesem Gebiet beleuchtet. Der Schwerpunkt liegt dabei auf Cycloadditionen (Huisgen-Reaktion), Aza-Ylidchemie und der Synthese von Heterocyclen. Weitere Reaktionen wie die Aza-Wittig-Reaktion, Sundberg-Umlagerung, Staudinger-Ligation, Boyer- und Boyer-Aube-Umlagerung, Curtius-Umlagerung, Schmidt-Umlagerung sowie die Hemetsberger-Umlagerung zeugen von der Vielfaltigkeit moderner Azid-Chemie.

Organische Azide – explodierende Vielfalt bei einer einzigartigen Substanzklasse

Recent developments in the carbodiimide chemistry

Nitrogen heterocycles are abundant in natural products and pharmaceuticals. An emerging interest among synthetic chemists is to apply vinyl azides as a pivotal three-atom synthon for the construction of structurally complex and diverse N-heterocyclic skeletons. The unique features of the azide group connected to an alkene moiety permit vinyl azides to function as electrophiles, nucleophiles, or radical acceptors; their access to diverse reaction pathways provides great opportunities to generate highly reactive intermediates with often unusual or unconventional reactivities. This tutorial review will systematically illustrate the reactivities of vinyl azides and describe recent breakthroughs in the development of new transformations that create N-heterocycles.

/pdf/reactivities-of-vinyl-azides-and-their-recent-applications-1is0k8yp08.pdf

Reactivities of vinyl azides and their recent applications in nitrogen heterocycle synthesis

Described is a scalable procedure for driving photochemical sytheses of trans-cyclooctene derivatives through metal complexation. During photoirradiation, reaction mixtures are continuously pumped through a column of a AgNO3-impregnated silica gel. The trans-cyclooctene derivative is selectively retained by the AgNO3-impregnated silica, but the cis-isomer elutes from the column back to the reaction flask, where it is photoisomerized and recirculated through the column. The method provides access to a range of usefully functionalized derivatives of trans-cyclooctene, including a derivative of 5-aza-trans-cyclooctene that underwent transannular cyclization upon treatment with bromine. The alkene stereochemistry is transferred with high fidelity to the hexahydropyrrolizine framework in the transannular cyclization.

A photochemical synthesis of functionalized trans-cyclooctenes driven by metal complexation.

Rearrangements of azidoquinones. XVI. Thermal and photolytic rearrangements of 2,5-diazido-1,4-quinones. Synthesis and chemistry of cyanoketenes

Rearrangement of azidoquinones. VII. Thermal cleavage of 2,5-diazidoquinones to cyanoketenes. Syntheses of tert-butylcyanoketene

Cycloaddition of tert-butylcyanoketene to 1,2-cyclononadiene and cis- and trans-cyclooctene

https://escholarship.org/content/qt5h90k54m/qt5h90k54m.pdf?t=nsm063

Rearrangement of azidoquinones IV. Ring expansion of 4-azido-1, 2-naphthoquinone

Rearrangements of azidoquinones. VIII. Photolytic rearrangement of 2,5-diazido-1,4-benzoquinones to 2-cyano-4-azido-1,3-cyclopentenediones, precursors to cyanoketenes

Walter Weyler

Papers

Rearrangements of azidoquinones. XVI. Thermal and photolytic rearrangements of 2,5-diazido-1,4-quinones. Synthesis and chemistry of cyanoketenes

Rearrangement of azidoquinones. VII. Thermal cleavage of 2,5-diazidoquinones to cyanoketenes. Syntheses of tert-butylcyanoketene

Cycloaddition of tert-butylcyanoketene to 1,2-cyclononadiene and cis- and trans-cyclooctene

Rearrangement of azidoquinones IV. Ring expansion of 4-azido-1, 2-naphthoquinone

Rearrangements of azidoquinones. VIII. Photolytic rearrangement of 2,5-diazido-1,4-benzoquinones to 2-cyano-4-azido-1,3-cyclopentenediones, precursors to cyanoketenes