Chiral cobalt(I) and nickel(0) complexes in the synthesis of nonracemic helicenes through the enantioselective [2+2+2] cyclotrimerisation of alkynes

0391515 - ÚOCHB 2014 RIV CH eng J - Článek v odborném periodiku
Heller, B. - Hapke, M. - Fischer, C. - Andronova, Angelina - Starý, Ivo - Stará, Irena G.
Chiral cobalt(I) and nickel(0) complexes in the synthesis of nonracemic helicenes through the enantioselective [2+2+2] cyclotrimerisation of alkynes.
Journal of Organometallic Chemistry. Roč. 723, Jan 1 (2013), s. 98-102. ISSN 0022-328X. E-ISSN 1872-8561
Grant CEP: GA AV ČR IAA400550916; GA MŠMT LC512
Institucionální podpora: RVO:61388963
Klíčová slova: asymmetric catalysis * helicene * cycloisomerisation * alkyne
Kód oboru RIV: CC - Organická chemie
Impakt faktor: 2.302, rok: 2013

The enantioselective intramolecular [2 + 2 + 2] cycloisomerisation of triynes under catalysis by chiral transition-metal complexes (Co-I, Ni-0) in order to receive nonracemic helicene derivatives was explored. The use of the chiral neomenthylindene Co-I complex led to a moderate 25% ee of tetrahydro[6] helicene, which was the first example of such a reaction catalysed by the chiral Co-I complex. The alternative Ni-0 catalysis employing privileged axially chiral monophosphines such as (-)-(aS)-NAPHEP led to tetrahydro [6] helicene with 64% ee, which is among the highest enantiomeric excesses so far observed for this Ni-0-catalysed reaction.
Trvalý link: http://hdl.handle.net/11104/0220539