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Multi‐Ferrocenyl Aryl Ethers – Applying Nucleophilic Aromatic Substitution Reactions to Aryl Fluorides
Author(s) -
Korb Marcus,
Lang Heinrich
Publication year - 2017
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.201600850
Subject(s) - chemistry , aryl , steric effects , substituent , medicinal chemistry , nucleophile , moiety , electrophile , ether , nucleophilic substitution , nuclear magnetic resonance spectroscopy , substitution reaction , stereochemistry , alkyl , organic chemistry , catalysis
The reaction of ferrocenol [FcOH; Fc = Fe(η 5 ‐C 5 H 5 )(η 5 ‐C 5 H 4 )] with aryl fluorides ArH 6– n F n ( n = 3–6) within a nucleophilic aromatic substitution reaction (S N Ar) gave ferrocenyloxy‐substituted fluorobenzenes of general type C 6 H 0–3 F 1–5 (OFc) 1–5 . For 1,3,5‐C 6 H 3 F 3 , 1,2,4,5‐C 6 H 2 F 4 , and C 6 H 6– n F n ( n = 5,6), one, two, and three F atoms, respectively, could be replaced by FcO units. The reaction of 1,4‐(OFc) 2 ‐C 6 F 4 with additional amounts of FcOH afforded the tetra‐ and penta‐substituted arenes 3,6‐F 2 ‐C 6 (OFc) 4 and C 6 F(OFc) 5 . Electrochemical investigations of both compounds showed four or five Fc/Fc + related reversible redox processes that were attributed to electrostatic interactions. The addition of C 6 F 6 as the electrophile after the anionic phospho‐Fries rearrangement of a ferrocenyl phosphate (1,3‐O→C migration) to the 1,2‐substituted ortho ‐phosphonato ferrocenol, resulted in the formation of the respective ortho ‐functionalized ether. The constitution of all compounds was verified by using 19 F NMR spectroscopy. Steric hindrance of the ortho ‐substituent resulted in a doubling of the signal sets for the C 6 F 5 moiety in the 13 C{ 1 H} and 19 F NMR spectra. The identity and substitution pattern of five compounds could also be determined by using single‐crystal X‐ray diffraction analysis, revealing the 1,4‐constitution of double functionalized derivatives, intermolecular non‐classical C–H ··· F interactions and π interactions.