Preparation and identification of bis(formylmethano)[60]-fullerene isomers: the first systematic study on bifunctionalized [60]fullerenes with dissymmetric addends

[摘要] Fourteen isomers of bis(formylmethano)C-60 were isolated and characterized. A mixture of the bisadducts was obtained by the reaction Of C-60 with an alpha-formylsulfonium ylide, and then separated into 15 fractions by preparative HPLC, preparative TLC, and recycling preparative HPLC. Fourteen of the fifteen fractions were found to consist of a single isomer, respectively, which were assigned to the trans-2 (3 diastereo-isomers), trans-3 (3 diastereo-isomers), trans-4 (3 diastereo-isomers), equatorial (2 diastereo-isomers) and cis-2 (3 diastereo-isomers) bisadducts by the comparison of their UV/vis spectra with those of the bisadducts obtained by the Bingel-Hirsch reaction. The H-1 and C-13 NMR analysis, the transformation of the formyl groups, and the dipole moment calculation clarified the stereochemistry of the substituents on the two cyclopropane bridge-head carbons (in/in, in/out, and out/out). (c) 2005 Elsevier Ltd. All rights reserved.

[发布日期] 2005-12-12

[关键词] bifunctionalization;diastereo-isomer;alpha-formylsulfonium ylide;fullerene;regio-isomer