Premium
Fullerene Dendrimers and Lipofullerenes with an Inherently Chiral Hexaaddition Pattern
Author(s) -
Djojo Francis,
Ravanelli Elena,
Vostrowsky Otto,
Hirsch Andreas
Publication year - 2000
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/(sici)1099-0690(200003)2000:6<1051::aid-ejoc1051>3.0.co;2-7
Subject(s) - chemistry , dendrimer , oxazoline , cyclopropanation , fullerene , ethyl diazoacetate , absolute configuration , styrene , stereoselectivity , octahedron , chirality (physics) , stereochemistry , cycloaddition , nuclear magnetic resonance spectroscopy , crystallography , catalysis , polymer chemistry , organic chemistry , crystal structure , copolymer , nambu–jona lasinio model , chiral symmetry breaking , physics , quantum mechanics , quark , polymer
The facile synthesis of enantiomerically pure C 3 ‐symmetrical fullerene dendrimers all ‐ R ‐ f A ‐ 7 , all ‐ S ‐ f C ‐ 8 , all ‐ R ‐ f C ‐ 9 , and all ‐ S ‐ f A ‐ 10 , as well as lipofullerenes all ‐ S ‐ f A ‐ 11 and all ‐ S ‐ f C ‐ 12 involving an octahedral [3:3] addition pattern is described. The C 3 symmetrical tris[bis(4‐phenyl‐2‐oxazoline)methano]fullerenes 1 , 2 , 3 , and 4 with known absolute configuration were used as precursors. The completion of the octahedral addition pattern was achieved by a threefold cyclopropanation with the dendritic 3,5‐dihydroxybenzylic bromomalonate 5 and the lipophilic dioctadecyl bromomalonate 6 . The absolute configurations of the precursor trisadducts were retained in the inherently chiral C 3 ‐symmetrical hexakisadducts 7‐12 . The structure and the isomeric purity of all hexakisadducts 7‐12 were unambiguously proven by NMR spectroscopy and other techniques. Preliminary experiments with the dendritic hexakisadducts all ‐ S ‐ f C 8 and all ‐ S ‐ f A 10 revealed that these macromolecular ligands posess catalytic properties with respect to stereoselective cyclopropanations of styrene with ethyl diazoacetate.