Gomberg-Hey reaction

This is sometimes called the Gomberg or the Gomberg - Hey reaction. 

Gabriel synthesis Gattermaim aldehyde reaction Gattermann reaction Gattermann-Kocll reaction Gomberg-Hey reaction Grignard reaction... 

The addition of aryl radicals, generated by chemical reduction of aryldiazonium salts, onto arenes in the Gomberg-Hey reaction is well established [163]. The addition of these radicals to alkenes in the Meerwein reaction is also well known [164], Aryl o-radicals generated by electrochemical reduction of aryl halides take part in similar reactions. Good yields of the products are obtained when the intermediate phenyl radical can react in an intramolecular manner. The addition step is then fast and competes successfully with further electron transfer to form the phenyl car-banion, followed by protonation. 

The effects of substituents upon the orientation of the entering phenyl radical and upon the reactivity of the pyridine nucleus have not received much attention. 4-Picoline is substituted by the 3-pyridyl radical (from the Gomberg-Hey reaction) to give a mixture containing 15% of the product of attack at the a-position (163) and 55% of product of attack at the /3-position (164). A very similar result was... 

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