Synthesis and X-ray crystal structure analysis of a scalemic C2-symmetric ferrocenophane

Abstract (R,R)-1,1′-Bis(2-chloroformyl-1-phenylethyl)ferrocene undergoes SnCl4 promoted intramolecular Friedel-Crafts cyclisation to give a 1.5:1 ratio of singly bridged ferrocenophane isomers. After separation of their corresponding methyl esters, the major isomer is converted into the novel C2-symmetric ferrocenophane (R,R,pS,pS)-1,1′-(1-phenyltrimethylene)-3,3′-(3-phenyltrimethylene)ferrocene, as determined by an X-ray crystal structure analysis.