Racemic and Optically Pure Heptahelicene-2-carboxylic Acid: Its Synthesis and Self-Assembly into Nanowire-Like Aggregates

0358625 - ÚOCHB 2012 RIV DE eng J - Journal Article
Rybáček, Jiří - Huerta-Angeles, Gloria - Kollárovič, Adrian - Stará, Irena G. - Starý, Ivo - Rahe, P. - Nimmrich, M. - Kühnle, A.
Racemic and Optically Pure Heptahelicene-2-carboxylic Acid: Its Synthesis and Self-Assembly into Nanowire-Like Aggregates.
European Journal of Organic Chemistry. -, č. 5 (2011), s. 853-860. ISSN 1434-193X. E-ISSN 1099-0690
R&D Projects: GA ČR(CZ) GAP207/10/2207; GA MŠMT LC512
Grant - others:FP6-European Commission(XE) 015847
Institutional research plan: CEZ:AV0Z40550506
Keywords : arenes * alkynes * cyclotrimerisation
Subject RIV: CC - Organic Chemistry
Impact factor: 3.329, year: 2011

Heptahelicene-2-carboxylic acid was effectively synthesised from suitably functionalised naphthalene building blocks. Methoxy-substituted 1,1'thyne-1,2-diylbis(2-but-3-yn-1-ylnaphthalene) was cyclised in the presence of CpCo(CO)2/PPh3 to 2-methoxy-7,8,11,12-tetrahydroheptahelicene, which was converted into heptahelicen-2-yl trifluoromethanesulfonate. This reactive intermediate underwent Pd(OAc)2/dppp-catalysed methoxycarbonylation reaction to provide, after hydrolysis, heptahelicene-2-carboxylic acid. The racemate was resolved into enantiomers by semipreparative HPLC on a chiral column. The helicity of (+)-(P)-heptahelicene-2-carboxylic acid was assigned by correlating its CD spectrum to that of the known (+)-(P)-heptahelicene. Racemic heptahelicene-2-carboxylic acid was deposited on calcite (10-14) to undergo self-assembly into nanowire-like aggregates as demonstrated by noncontact atomic force microscopy (NC-AFM).
Permanent Link: http://hdl.handle.net/11104/0196595