Formation of cis-3 bis-adducts

Other examples include the fullerene dendrimer 57 [61] with a molecular mass of 7344 Da, dendrimer 59 featuring a bis(l,10-phenanthroline)copper(II) core and 16 peripheral fullerene groups (molecular mass 31601 Da) [72,73], and porphyrin derivatives with two [74] and four (58) [75] appended fullerenes. 

Since cis-3, trans-3, and trans-2 bis-adducts of 50 with identical addends are chiral as a result of inherently chiral functionalization patterns [10, 44-46], it was of interest to explore whether Bingel macrocyclizations with bismalonates bridged by non-racemic tethers would provide an enantioselective synthesis of these compounds. An overall enantioselective synthesis of optically active Cgg bis-adducts had been achieved previously by asymmetric Sharpless bis-osmylation [77] however, this sequential bis-func-tionalization lacks the regioselectivity of the Bingel macrocyclization, and therefore requires tedious regioisomer separations. 

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