Addition of photochemically generated acylnitrenes to C60. Synthesis of fulleroaziridines and thermal rearrangement to fullerooxazoles

Preparation and Characterization of Sulfonyl‐Azafulleroid and Sulfonylaziridino‐Fullerene Derivatives

“…[2,9Ϫ11] Nitrenes generated in situ by photolysis or thermolysis of azides add to fullerenes in [2ϩ1] cycloadditons yielding exclusively closed [6,6]-bridged aziridino-fullerenes. [9,10,23] …”

Cycloadditions

“…Photochemical reaction between aroylazide or arylazide in halogenated solvents proceeds, probably, also via the nitrene intermediate [401,402]. This is supported by the fact that almost only the [6,6] adduct is formed.…”

“…The corresponding [5,6] bridged isomer is -if at all -formed only in small amounts, probably via a direct addition to the [5,6] bond [394]. Nitrenes have been generated by thermolysis of azido-formic esters [172,[395][396][397][398][399][400], photolysis of aroyl azides [401] or aryl azide [402], elimination of O-4-nitrophenylsulfonylalkylhydroxamic acid [403] or reaction of amines with Pb(OAc) 4 [404].…”

Ferric perchlorate-mediated radical reactions of [60]fullerene

“…The synthesis of fullerooxazoles had also been achieved by a two-step reaction starting from C 60 , that is, photochemical reactions of C 60 with acyl azides [55], or thermal reactions with azidoformates and hydroxamic acid derivatives [56,57], followed by rearrangement of the formed fulleroaziridines to fullerooxazoles. Our current one-step approach to access fullerooxazoles by employing cheap and easily available nitriles and Fe(ClO 4 ) 3 exhibited obvious advantages over the reported methods [5557].…”