title: Single Electron Transfer-Promoted Photochemical Reactions of Secondary N-Trimethylsilylmethyl-N-benzylamines Leading to Aminomethylation of Fullerene C60.
abstract: Photoreactions between C60 and secondary N-trimethylsilylmethyl-N-benzylamines were explored to evaluate the feasibility of a new method for secondary aminomethylation of electron acceptors. The results show that photoreactions of C60 with these secondary amines in 10% EtOH-toluene occur to form aminomethyl-1,2-dihydrofullerenes predominantly through a pathway involving single electron transfer (SET)-promoted formation of secondary aminium radicals followed by preferential loss of the α-trimethylsilyl group. The aminomethyl radicals formed in this manner then couple with C60 or C60(•-) to form radical or anion precursors of the aminomethyl-1,2-dihydrofullerenes. In contrast to thermal and photochemical strategies developed previously, the new SET photochemical approach using α-trimethylsilyl-substituted secondary amines is both mild and efficient, and as a result, it should be useful in broadening the library of substituted fullerenes. Moreover, the results should have an impact on the design of SET-promoted C-C bond forming reactions. Specifically, introduction of an α-trimethylsilyl group leads to a change in the chemoselectivity of SET-promoted reactions of secondary amines with acceptors that typically favor aminium radical N-H deprotonation, leading to N-C bond formation. Finally, symmetric and unsymmetric fulleropyrrolidines are also generated in yields that are highly dependent on the electronic properties of arene ring substituents in amines, irradiation time, and solvent.
authors.affiliation: Department of Chemistry, Yeungnam University , Gyeongsan, Gyeongbuk 712-749, Korea.
authors.forename: Suk Hyun
authors.initials: SH
authors.lastname: Lim
authors.affiliation: Department of Energy Convergence Engineering, Yeungnam University , Gyeongsan, Gyeongbuk 712-749, Korea.
authors.forename: Ho Cheol
authors.initials: HC
authors.lastname: Jeong
authors.affiliation: Department of Chemistry, Yeungnam University , Gyeongsan, Gyeongbuk 712-749, Korea.
authors.forename: Youngku
authors.initials: Y
authors.lastname: Sohn
authors.affiliation: Department of Chemistry, Yeungnam University , Gyeongsan, Gyeongbuk 712-749, Korea.
authors.forename: Young-Il
authors.initials: YI
authors.lastname: Kim
authors.affiliation: Department of Chemistry, Yeungnam University , Gyeongsan, Gyeongbuk 712-749, Korea.
authors.forename: Dae Won
authors.initials: DW
authors.lastname: Cho
authors.affiliation: Department of Chemistry, Soongsil University , Seoul 156-743, Korea.
authors.forename: Hee-Jae
authors.initials: HJ
authors.lastname: Woo
authors.affiliation: Department of Chemistry, Soongsil University , Seoul 156-743, Korea.
authors.forename: Ik-Soo
authors.initials: IS
authors.lastname: Shin
authors.affiliation: Department of Chemistry, Pusan National University , Busan 609-735, Korea.
authors.forename: Ung Chan
authors.initials: UC
authors.lastname: Yoon
authors.affiliation: Department of Chemistry and Chemical Biology, University of New Mexico , Albuquerque, New Mexico 87131, United States.
authors.forename: Patrick S
authors.initials: PS
authors.lastname: Mariano