Search for Conglomerate in Set of [7]Helquat Salts: Multigram Resolution of Helicene-Viologen Hybrid by Preferential Crystallization

0392346 - ÚOCHB 2014 RIV US eng J - Journal Article
Vávra, Jan - Severa, Lukáš - Císařová, I. - Klepetářová, Blanka - Šaman, David - Koval, Dušan - Kašička, Václav - Teplý, Filip
Search for Conglomerate in Set of [7]Helquat Salts: Multigram Resolution of Helicene-Viologen Hybrid by Preferential Crystallization.
Journal of Organic Chemistry. Roč. 78, č. 4 (2013), s. 1329-1342. ISSN 0022-3263. E-ISSN 1520-6904
R&D Projects: GA ČR GAP207/10/2391; GA ČR(CZ) GAP206/12/0453; GA ČR GP203/09/P485; GA ČR GA203/09/0705
Institutional support: RVO:61388963
Keywords : attrition-enhanced deracemization * helquats * hexahelicene * tetraphenylenes
Subject RIV: CC - Organic Chemistry
Impact factor: 4.638, year: 2013

Investigation of a set of 12 [7]helquat salts by X-ray crystal diffraction led to identification of conglomerate behavior in bis(trifluoroacetate) salt [2][CF3CO2](2). This is to demonstrate that a systematic search for conglomerates can be performed for a given helicenoid enabling straightforward multigram resolution via preferential crystallization. Subsequently, preferential crystallization of this chiral helicene viologen hybrid has been established to obtain pure P and M enantiomers on a multigram scale, 5 g each. Furthermore, preparation of nonracemic samples of [7]helquat 2 via diastereomeric (R,R)-dibenzoyltartrate salts is described, and determination of absolute configuration and racemization barrier is also reported.
Permanent Link: http://hdl.handle.net/11104/0221237