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Multiple Acetylation of Pentaphenylferrocene – Synthesis and Asymmetric Reduction of 1‐Acetyl‐1′,2′,3′,4′,5′‐penta( para ‐acetylphenyl)ferrocene
Author(s) -
Arthurs Ross A.,
Richards Christopher J.
Publication year - 2018
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201800129
Subject(s) - chemistry , enantiopure drug , ferrocene , acetylation , yield (engineering) , ketone , reagent , medicinal chemistry , stereochemistry , organic chemistry , enantioselective synthesis , catalysis , electrochemistry , biochemistry , materials science , electrode , metallurgy , gene
The Friedel–Crafts acetylation of pentaphenylferrocene has been revisited using 1.1 equivalents of AcCl/AlCl 3 in CH 2 Cl 2 at room temperature leading to the synthesis of 1‐acetyl‐1′,2′,3′,4′,5′‐pentaphenylferrocene (78 % yield). Increased quantities of reagents and longer reaction times resulted in acetylation of the phenyl groups exclusively at the para ‐position, this methodology culminating in the synthesis of 1‐acetyl‐1′,2′,3′,4′,5′‐penta( para ‐acetylphenyl)ferrocene (32 % for a two step process). Subsequent asymmetric reduction of all six ketone functionalities with BH 3 · SMe 2 catalysed by 60 mol‐% ( S )‐CBS proceeded in 81 % yield to give ( R , R , R , R , R , R )‐1‐(α‐hydroxyethyl)‐1′,2′,3′,4′,5′‐penta[ para ‐(α‐hydroxyethyl)phenyl]ferrocene, a highly functionalised enantiopure building block for the synthesis of ligands and materials.