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Insertion of Fischer Carbene Complexes into the Carbon-Carbon Bond of 1,2-Diphenylcyclopropenone: Formation of Cyclobutenones and o- and p-Methoxyphenol Derivatives

1994-08-01
Zora, Metin
Herndon, James W.
Thereactionbetween1,2-diphenylcyclopro-penoneandFischercarbenecomplexeshasbeeninves-tigated.Thereactionproducedamixtureofdipheny-lacetyleneandcyclobutenones.Whena,ß-unsaturatedcarbenecomplexeswereemployed,benzannulationprod-uctsanddiphenylacetylenewereproduced.Amecha-nisminvolvingmetallacyclobutenoneformation,followedbyeithercarbeneinsertionandreductiveeliminationorfragmentationhasbeenproposed.Recently,wereportedthatcarbon—carbonbondin-sertionisthemajorreactionpathwaywhenFischercarbenecomplexesreactwith1,2-cyclobutenediones,1affording4-cyclopentene-l,3-dionesand/or5-alkylidene-furanones.Otherstrainedringsmightleadtoinsertionproductsaswell.Avarietyofadditionalringsystemsweretestedinthisreaction,includingcyclobutenones,cyclobutenes,cyclopropanes,cyclopentadienones,andcyclopropenones.Ofthese,onlythecyclopropenoneringsystemaffordedcarbon—carbonbondinsertionproductswhentreatedwithFischercarbenecomplexes.Hereinwereportthereactionbetween1,2-diphenylcyclopro-penoneandFishercarbenecomplexes.