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Hydrogen Bonded Phenol‐Quinolines with Highly Controlled Proton‐Transfer Coordinate
Author(s) -
Parada Giovanny A.,
Glover Starla D.,
Orthaber Andreas,
Hammarström Leif,
Ott Sascha
Publication year - 2016
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/ejoc.201600460
Subject(s) - chemistry , intramolecular force , hydrogen bond , quinoline , phenols , phenol , ring (chemistry) , molecule , photochemistry , stereochemistry , organic chemistry
A series of polycyclic phenols with intramolecular hydrogen bonds (IMHB) to quinolines was synthesized by Friedländer annulation of cycloalkanone‐functionalized anisoles with 2‐aminobenzaldehyde. The prepared compounds represent the first series of IMHB phenols in which the substitution and conjugation patterns between the phenols and the hydrogen bond acceptors are kept constant, and in which comparable electronic interaction between the two subunits is thus ensured. The distance and relative orientation between the phenolic OH and the quinolone nitrogen atom is controlled by 1,3‐cycloalkadienes of different ring sizes to which the phenol and quinoline subunits are formally annulated. 1 H δ (OH) chemical shift and X‐ray crystal structure characterization support the conclusion that the size and conformational preference of the 1,3‐cycloalkadiene rings control the H‐bond geometry and strength. As a result, the oxygen to nitrogen distances differ by as much as 0.30 Å across the series.