Highly enantioselective conjugate addition of nitromethane to chalcones using bifunctional cinchona organocatalysts.

Highly enantioselective conjugate addition of nitromethane to chalcones using bifunctional cinchona organocatalysts.

Organic letters (2005-05-07)

Benedek Vakulya, Szilárd Varga, Antal Csámpai, Tibor Soós

ABSTRAKT

Cinchona alkaloid-derived chiral bifunctional thiourea organocatalysts were synthesized and applied in the Michael addition between nitromethane and chalcones with high ee and chemical yields.

MATERIAŁY

Numer produktu

Marka

Opis produktu

73478

Sigma-Aldrich

Nitromethane, puriss., absolute, over molecular sieve, ≥98.5% (GC)

690481

Sigma-Aldrich

N-[3,5-Bis(trifluoromethyl)phenyl]-N′-[(8a,9S)-6′-methoxy-9-cinchonanyl]thiourea, 90%

690384

Sigma-Aldrich

N-[3,5-Bis(trifluoromethyl)phenyl]-N′-[(8a,9S)-10,11-dihydro-6′-methoxy-9-cinchonanyl]thiourea, 90%

270423

Sigma-Aldrich

Nitromethane, suitable for HPLC, ≥96%

360554

Sigma-Aldrich

Nitromethane, ACS reagent, ≥95%

230731

Sigma-Aldrich

Nitromethane, ReagentPlus^®, ≥99.0%