Source of fluorocarbenes

Attempted insertions of fluorocarbenes into Sn—Mn and Sn—Fe bonds were unsuccessful thus, the thermal reaction of (CO)sMnSnMe3 with Me3SnCF3 (a good source of carbene CF2) led instead to a disproportionation reaction involving formation of (CO)5MnSnMe2(CF3) and SnMe4344. 

Miyazaki and Yamada report that irradiation of cyclopentadiene in an argon matrix with a super-high-pressure Hg lamp results in the formation of bicyclo[2.1.0]pent-2-ene. By irradiation at shorter wavelengths the initial product is transformed into allylacetylene and vinylallene. The photochemical ring opening of the cyclohexadiene moiety within the triterpenoids (106) yields the corresponding trienes. The tricyclo[4.3.1.0]dienes (107) have been used as a source of some fluorocarbenes irradiation affords the carbenes with indane produced as the by-product. 

The photolysis and pyrolysis of difluorodiazirine has been shown to involve difluoromethylene and stereospecific addition to 2-butene indicates that it is probably in a singlet state. In argon or nitrogen matrices, Cp2 has been detected by spectroscopic measurements . Products arising from the thermolysis or photolysis of fluoromethoxydiazirine, cyanofluorodiazirine, difluoroaminodiazirine and chlorofluorodiazirine have been reported the main feature of these reactions is that the intermediate carbene in all cases can be trapped by olefin reagents, whereas fluorocarbenes from other sources are quite unreactive. 

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