Unexpected Reactions of [60]Fullerene Involving Tertiary Amines and Insight into the Reaction Mechanisms

Abstract

Thermal reactions of [60]fullerene with amino acid ester hydrochlorides and triethylamine in o-dichlorobenzene at reflux afforded pyrrolidinofullerene derivatives containing the CH(3)CH moiety and originating from triethylamine through an unusual C-N bond cleavage. Detailed investigation of these thermal reactions resulted in the discovery of unprecedented reactions between C(60) and tertiary amines and of reactions of C(60) with tertiary amines and aldehydes, giving cyclopentafullerene derivatives with high stereoselectivity. Plausible reaction mechanisms for the product formation involving the uncommon C-N bond cleavage of tertiary amines were proposed on the basis of extensive experimental results.

Regioselective Thermal Reaction between Triethylamine and C60 Revisited: X‐ray Confirmation of the Pentane‐Fused Adduct and in Situ Mechanism Study

“…[6,7] In contrast, a more plausible mechanism for the thermal reaction between C 60 and TEA was regarded to be a 1,3-dipolar cycloaddition process, involving acetaldehyde and diethylamine intermediates (Figure 8, a). [10] To confirm this, we try to identify the existence of the intermediates with GC-MS spectroscopy. Indeed, characteristic mass/ion peaks of acetaldehyde at m/z 44.0 (Figure 8, b) and diethylamine at m/z 73.1 (Figure 8, c) were detected, unambiguously confirming the 1,3-dipolar cycloaddition mechanism.…”

“…[9] Recently, Wang group investigated the reaction of C 60 and TEA under thermal conditions, and proposed the formation of the pentane cycloaddition derivative (Figure 1, D). [10] So far, there are no Xray crystallographic reports for the structure of fullerene derivatives from the reaction between C 60 and TEA, nor the mechanism has been fully understood.…”

Solution phase n-doping of C60and PCBM using tetrabutylammonium fluoride

“…28 Wang et al has also reported on the unusual C-N bond cleavage when C 60 is reacted with triethylamine. 36 The formation of numerous reaction products would potentially result in the formation of sources of free radicals or charge carrier traps as observed by Duan et al when analyzing interactions of amine functionalized fullerenes and polymers with an OPV active layer. 10 …”

On the Regioselective Intramolecular Nucleophilic Addition of Thiols to C60

“…Interestingly, compound 15 has recently been obtained in 39 % yield by heating C 60 with sarcosine ethyl ester hydrochloride and Et 3 N in o-dichlorobenzene (o-DCB) at 220°C under dark and aerobic conditions through a mechanism involving radical species. [17] Although the mechanism for the formation of compound 15 lacking the thiol moiety from 14 is not clear, other related cases, probably involving a radical mechanism, have been reported in the literature. [18] It is worth mentioning that although compound 15 was not the goal in this reaction (C 60 , 12, and 13), it does provide a facile access to 2-methyl-substituted pyrrolidinofullerenes which would otherwise require the presence of acetaldehyde as a reagent in Prato's protocol.…”