Structural Reassignment of the Mono‐ and Bis‐Addition Products from the Addition Reactions of N‐(Diphenylmethylene)glycinate Esters to [60]Fullerene under Bingel Conditions.

The addition of N-(diphenylmethylene)glycinate esters (Ph2C=NCH2CO2R) to [60]fullerene under Bingel conditions gives [60]fullerenyldihydropyrroles and not methano[60]fullerenyl iminoesters [C60C(CO2R)(N=CPh2)] as previously reported. Unequivocal evidence for the structure of C60C(CO2Et)(N=CPh2) was provided by INADEQUATE NMR studies on C enriched material. New mechanistic details are proposed to account for the formation of [60]fullerenyldihydropyrroles and their reductive ring-opening reactions. Introduction The reaction of activated methylenes (WCH2W’) with [60]fullerene in the presence of a brominating agent and base is known as the Bingel reaction and commonly yields fused 3-membered ring adducts (methano[60]fullerenes, C60CW(W’)). In a recent paper we reported that the addition of N-(diphenylmethylene)glycinate esters 2a-d to [60]fullerene under Bingel conditions gave methano[60]fullerenyl iminoesters 1a-d, and that tethered bis-N-(diphenylmethylene)glycinate esters, derived from metaand para-benzenedimethanol scaffolds, gave the corresponding bis-methano[60]fullerenyl iminoesters 2. The structures of compounds 1a-d were based upon the observation of a single sp fullerene resonance (between 82-83) in the C NMR spectra (4:6