Reversal of the sense of enantioselectivity between 1-and 2-aza[6]helicenes used as chiral inducers of asymmetric autocatalysis

0475000 - ÚOCHB 2018 RIV GB eng J - Článek v odborném periodiku
Matsumoto, A. - Yonemitsu, K. - Ozaki, H. - Míšek, Jiří - Starý, Ivo - Stará, Irena G. - Soai, K.
Reversal of the sense of enantioselectivity between 1-and 2-aza[6]helicenes used as chiral inducers of asymmetric autocatalysis.
Organic & Biomolecular Chemistry. Roč. 15, č. 6 (2017), s. 1321-1324. ISSN 1477-0520. E-ISSN 1477-0539
Grant CEP: GA ČR(CZ) GA14-29667S
Institucionální podpora: RVO:61388963
Klíčová slova: azahelicene * Soai reaction * asymmetric autocatalysis
Obor OECD: Organic chemistry
Impakt faktor: 3.423, rok: 2017
http://pubs.rsc.org/en/content/articlehtml/2013/ob/c6ob02745h

Reversal of the sense of enantioselectivity was observed between 1-aza[6]helicene 2 and 2-aza[6]helicene 3 employed as chiral inducers of asymmetric autocatalysis of pyrimidyl alkanol. In the presence of (P)-(+)-1-aza[6]helicene 2, the reaction of pyrimidine-5-carbaldehyde 1 with diisopropylzinc afforded, in conjunction with asymmetric autocatalysis, (S)-pyrimidyl alkanol 4 with high ee. Surprisingly, the reaction in the presence of (P)-(+)-2-aza[6]helicene 3 gave the opposite enantiomer of (R)-alkanol 4 with high ee. In the same manner, (M)-(-)-2 and (M)-(-)-3 afforded (R)-and (S)-alkanol 4, respectively. The sense of enantioselectivity is controlled not only by the helicity of the azahelicene derivatives but also by the position of the nitrogen atom.
Trvalý link: http://hdl.handle.net/11104/0271883