Synthesis and orthogonal functionalization of [60]fullerene e,e,e-trisadducts with two spherically defined addend zones.
e,e,e-Trisadducts 13 and 15 have been prepared by a highly regioselective threefold cyclopropanation of tripodal malonates 10 and 12 with C60. The yield and regioselectivity depend on the length and structure of the tethers that connect the malonate units to the focal benzene core of 13-15. As a consequence of the template-directed synthesis, all e,e,e-trisadducts were formed as in/out isomers exclusively and contain two spherically well-defined addend zones with equatorial and polar orientation, respectively. By variation of the outer malonate termini of the tethers, selective functionalization of the equatorial addend zone could be achieved, thus leading to fine-tuning of intermolecular interactions, such as solubility or aggregation phenomena. After removal of the focal benzene moiety in 14 and 15, selective functionalization of the polar addend zone could be achieved. Strong intramolecular hydrogen-bonding networks of the polar substituents in the polar addend zone could be observed by 1H NMR spectroscopic analysis. By orthogonal functionalization of both addend zones, fullerene derivatives 44-48 could be synthesized as one single in/out isomer, thus greatly enhancing the potential of e,e,e-trisadducts as building blocks in supramolecular architectures.
Beuerle
Florian
F
Department of Chemistry and Pharmacy, Interdisciplinary Center of Molecular Materials (ICMM), Friedrich-Alexander-Universität Erlangen-Nürnberg, Henkestrasse 42, 91054 Erlangen, Germany.
Hirsch
Andreas
A
D001555:Benzene Derivatives / Q000138:chemical synthesis* / Q000737:chemistry; D003521:Cyclopropanes / Q000737:chemistry*; D037741:Fullerenes / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008314:Malonates / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D013237:Stereoisomerism
D001555:Benzene Derivatives; D003521:Cyclopropanes; D037741:Fullerenes; D008314:Malonates; C069837:fullerene C60