Highly Functionalized Bicyclo[2.2.2]octenone-Fused [60]Fullerenes from Masked o-Benzoquinones and C₆₀

Abstract

[reaction: see text] The Diels-Alder reactions of masked o-benzoquinones (MOBs) with [60]fullerene, affording novel and highly functionalized bicyclo[2.2. 2]octenone-fused [60]fullerene derivatives, are described.

Oxidative Dearomatization of Phenols and Anilines via λ3- and λ5-Iodane-Mediated Phenylation and Oxygenation

“…The presence of a methyl group at the 3-position of 1a was chosen in order to block [4+2] dimerization of 3a [ 5 ]. Indeed, the presence of such a small electron-releasing group at the corresponding 5-position of cyclohexa-2,4-dienones is known to block their dimerization [ 22 , 23 ]. Treatment of 1a with tetrafluoroboro(diphenyl)-λ 3 -iodane [ 24 ] in DMF at room temperature using weak bases such as pyridine or triethylamine failed to initiate any reaction ( Table 1 , entries 1 and 2).…”

“…This hypothesis was confirmed using the di- and trimethylphenols 1c and 1d , which gave rise to the formation of the desired cyclohexa-2,4-dienones 3c and 3d in 37% and 42%, respectively ( Table 2 , entries 2 and 3). Moreover, these cyclohexa-2,4-dienones are stable compounds that do not spontaneously engage in [4+2] dimerization, despite the absence of an alkyl substituent at their 5-position [ 22 , 23 ]. Interestingly, 2,4,6-trimethylphenol ( 1d ) also led to phenylation at the methylated 4-position (entry 3).…”

Masked o-benzoquinone strategy in organic synthesis: Short and efficient construction of cis-decalins and linear triquinanes from 2-methoxyphenols

“…The electron-deficient dienophiles such as methyl acrylate [2], methyl vinyl ketone [2], methyl methacrylate [2], acrolein [11], methacrolein [11], and even [60]fullerene [12] participated in the Diels-Alder reactions with in situ generated MOBs to afford the corresponding cycloadducts in high yields (Scheme 3). The electron-rich dienophiles such as benzyl vinyl ether, dihydrofuran, phenyl vinyl sulfide, and conjugative dienophile styrene [8a-c] underwent Diels-Alder cycloaddition with MOBs to furnish highly functionalized bicyclo[2.2.2]octenones in high yields (Scheme 3).…”

Organofullerene Materials

“…Recently, the reaction of "masked" ortho-benzoquinone [92] with C 60 was tested [93]. The [4+2] cycloaddition reaction of such electron-deficient dienes with fullerenes resulted in the formation of highly functionalized bicyclo[2.2.2] octenone-fused fullerenes.…”