close

Вход

Забыли?

вход по аккаунту

?

код для вставки
2005
Enantioselective syntheses
O 0031
Trends in Asymmetric Michael Reactions Catalyzed by Tripeptides in Combinawith an Achiral Additive in Different Solvents. — Three tripeptides are pre04- 025 tion
pared by standard peptide chemistry. They are tested as chiral catalysts in the presence
of trans-2,5-dimethylpiperazine as an achiral additive in the asymmetric Michael addition of 2-nitropropane to cyclohexenone using several solvents. While two acyclic amino acid derived tripeptides show only moderate enantioselectivities resulting from
hydrogen bond formation, the tris(4-aminoproline) based tripeptide TPC induces enantioselectivities of up to 80% e.e. due to the action of the aminocatalytic effect. The best
solvent in view of both yield and enantioselectivity, CHCl3, was selected for the application of the reaction to various nitroalkanes (IV). — (TSOGOEVA*, S. B.; JAGTAP,
S. B.; ARDEMASOVA, Z. A.; KALIKHEVICH, V. N.; Eur. J. Org. Chem. 2004, 19,
4014-4019; Inst. Org. Biomol. Chem., Georg-August-Univ., D-37077 Goettingen,
Germany; Eng.) — Kieslich
Документ
Категория
Без категории
Просмотров
0
Размер файла
23 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа