Formyl azide

Recently, the same procedure has been used by Williams and coworkers in their approach to the natural product (-)-stemonine (7-18) [10], an alkaloid which exhibits broad biological activity [11]. Conversion of the formyl azide 7-16 in a Staudinger reaction with ethyldiphenylphosphine first generated a phosphineimide which was used for the subsequent aza-Wittig process (Scheme 7.7). The furnished seven-... 

L abbe and coworkers studied the synthesis and thermolysis of 5-azido-4-formyl-oxazoles. They found, for example, that azides 17a-b rearrange at room temperature to yield isolable, isomeric oxazoles 18a-b. 

A diazo group can be introduced adjacent to a single carbonyl group indirectly by first converting the ketone to an a-formyl ketone (10-118), and then treating it with tosyl azide. As in the similar cases of 12-7 and 12-8, the formyl group is cleaved... 

Amino-substituted selenophenes are in general unstable compounds, and are conveniently isolated as IV-acetyl or iV-formyl derivatives. An ortho situated electron-attracting substituent such as acetyl, formyl or nitro renders the amino compounds stable. Derivatives of this type can be diazolized and the resulting diazonium salts converted into azides (by reaction with azide ion) (75CR(C)(281)317) and selenocyanates (by reaction with selenocyanide ion) (79BSF(2)237). 3-Acetamidoselenophene can be thiocyanated or selenocyanated in the 2-position by treatment with bromine and potassium thiocyanate or potassium selenocyanate, respectively (78TL1797). 

The thermal Curtius rearrangement of formyl, acetyl, and benzoyl azides was studied by DFT.78 The authors conclude that the reaction occurs by a concerted mechanism and not by the alternative nitrene intermediate. 

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