The Course of the Reaction of Azobenzene with Chromium Carbene Complexes

Article abstract of DOI:10.1021/ja00208a010

The dark reaction between cis-azobenzene and pentacarbonyl<(methoxy)(methyl)carbene>chromium(0) was followed by 1H NMR spectroscopy.The intervention of two discrete intermediates-thought to be a zwitterion and a metallacycle-was detected.Carrying out the reaction in hexane under a carbon monoxide atmosphere caused the reaction to stop at the metallacycle stage.Photolytic decomposition of this produced 1,3-diazetidinone and imidate products, as well as small amounts of azobenzene. 1,2-Diazetidinone products were thought to result from a primary photoreactionbetween cis-azobenzene and a photogenerated (methoxy)(methyl)ketene chromium complex.