Circular Dichroism of 9,10-Dihydrophenanthrene Derivatives Reveals both the Absolute Configuration and Conformation: A Novel Approach to Mislow's Helicity Rule

Abstract

Dreierpacks: Die Kristallisation von 1,4‐Diazabicyclo[2.2.2]octan (A) mit einem, zwei oder drei unterschiedlichen 4‐substituierten Phenolen (B, C, D) führt zu Cokristallen (z. B. AB2, links) oder festen Lösungen (z. B. A(B,C,D)2, rechts). Diese organischen Mehrkomponentenfestkörper enthalten supramolekulare Dreimolekülaggregate als Wiederholungseinheiten.

Circular dichroism spectra, optical rotations and absolute configurations of cis‐dihydrodiol metabolites of quinoline and derivatives: The role of the nitrogen atom

“…We observed excellent agreement between the experimentally measured, and the calculated, optical rotation data, even though the former were obtained in methanol solution. It has been reported before that intramolecular hydrogen bonded structures can still be retained in methanol solution 50. In all cases measured and calculated OR values at the sodium D‐line were positive.…”

Conformational aspects in the studies of organic compounds by electronic circular dichroism

“…63 In 9,10-dihydrophenanthrenes (31, formally 1,1 0 -biphenyl derivatives, Scheme 7), the ECD spectrum reveals the M/P chirality of the biphenyl core together with the axial/equatorial arrangement of the 9,10 substituents Y/Y 0 , two aspects directly related to each other. 64 A noteworthy class of compounds containing multiple aromatic chromophores is represented by tripodal complexes of Zn 2+ , Cu + and Cu 2+ with multidentate ligands of the type 32 (Scheme 7), formed by derivatization of chiral primary amines with 2-bromomethyl quinolines, as reported by Canary and coworkers. In the complexes, the aromatic moieties adopt a stable propeller-like conformation, which depends on the metal coordination geometry.…”

Lignans from Schisandra sphenathera Rehd. et Wils. and semisynthetic schisantherin A analogues: Absolute configuration, and their estrogenic and anti-proliferative activity

“…Such a correlation was first observed by Ikeya et al [14,24] and has been applied to establish the absolute configuration of several dibenzocyclooctadiene lignans and related compounds. It is based on the more general and well-known biaryl helicity rule, established by Mislow [25] in the early 1960s and subsequently interpreted on a theoretical ground [26,27]. Schisandrin A1 (1) contains however, in addition to the substituted dibenzocyclooctadiene, a second strong chromophore, the benzoate, which cannot be overlooked in the CD analysis.…”