ja962509t_si_002.pdf (194.25 kB)
Photocycloaddition of Cyclic 1,3-Diones to C60
journal contribution
posted on 1997-08-06, 00:00 authored by Anton W. Jensen, Anthony Khong, Martin Saunders, Steven R. Wilson, David I. SchusterIrradiation of cyclic 1,3-diones (1a and 2a)
with C60 in benzene leads to formation of two
fused
furanylfullerenes, one achiral (3) and the other chiral
(4), as opposed to the expected De Mayo
cyclooctane-1,3-dione addition product. The same products are obtained when
1,3-diones are replaced with trimethylsilyl-protected
diones (1b and 2b). The adduct structures
were characterized by MS (ESI and MALDI), IR, UV, 1H NMR,
13C
NMR, and 3He NMR spectroscopy. These fullerene
adducts presumably are formed after initial [2 + 2]
photocycloaddition, followed by either intermolecular
oxidation of the cyclobutyl intermediates (5−8)
by 1O2 to
form 3 or intramolecular oxidation of the
appended group by the triplet fullerene moiety of
5−8 to form 4.