Premium
Tropos , Nevertheless Conformationally Stable Biphenyl Derivatives
Author(s) -
Haberhauer Gebhard,
Tepper Christina,
Wölper Christoph,
Bläser Dieter
Publication year - 2013
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.201300087
Subject(s) - chemistry , biphenyl , conformational isomerism , substituent , stereochemistry , solid state , atropisomer , derivative (finance) , molecule , organic chemistry , financial economics , economics
Abstract Biphenyl derivatives with small substituents in the ortho and ortho′ positions are called tropos . Due to the low rotation barrier around the C–C bond connecting the two phenyl units, the isolation of only one conformer is not possible; thus they are conformationally unstable. Using DFT calculations, we were able to show that using a suitable peptidic bridging unit, biphenyl systems can become conformationally stable. This stabilization should be independent of the type of substituent in the ortho and ortho′ positions. Some of the proposed biphenyl derivatives were successfully synthesized and studied in solution and solid state. The recorded VT‐NMR, 2D‐NMR and CD spectra show that all biphenyl derivatives exhibit the P conformation. The preference for the P conformation is confirmed by the structure of a biphenyl derivative in solid state.