Graham reaction

{{Short description|Oxidation reaction in organic chemistry}}

In organic chemistry, the Graham reaction is an oxidation reaction that converts an amidine into a diazirine using a hypohalite reagent. The halide of the hypohalite oxidant, or another similar anionic additive to the reaction, is retained as a substituent on the diazirine product. The reaction was first reported in 1965.{{Cite journal|title = The Halogenation of Amidines. I. Synthesis of 3-Halo- and Other Negatively Substituted Diazirines|journal = Journal of the American Chemical Society|date = 1965-10-01|issn = 0002-7863|pages = 4396–4397|volume = 87|issue = 19|doi = 10.1021/ja00947a040|first = W. H.|last = Graham}} Various reaction mechanisms have been proposed.{{cite web |url= https://www.ch.imperial.ac.uk/rzepa/blog/?p=20464 |title= The Graham reaction: Deciding upon a reasonable mechanism and curly arrow representation |first= Henry |last= Rzepa |author-link= Henry Rzepa |date= February 18, 2019 }}{{cite journal |title= Mechanism of Graham's reaction |first1= Robert A. |last1= Moss |first2= Joanna |last2= Wlostowska |first3= Wenjeng |last3= Guo |first4= Michal |last4= Fedorynski |first5= James P. |last5= Springer |first6= Jordan M. |last6= Hirshfield |journal= J. Org. Chem. |year= 1981 |volume= 46 |issue= 24 |pages= 5048–5050 |doi= 10.1021/jo00337a061 }}

:300px

Amidine substrates for the reaction can easily be formed from the corresponding nitriles via the Pinner reaction. The halide substituent in the diazirine product can be displaced by a various nucleophiles.{{Cite journal|title = Diazirines: Carbene Precursors Par Excellence|journal = Accounts of Chemical Research|date = 2006-02-09|issn = 0001-4842|pages = 267–272|volume = 39|issue = 4|doi = 10.1021/ar050155h|first = Robert A.|last = Moss|pmid = 16618094}}

:File:Diazirine Exchange.svg