- Asymmetric amination of meso-epoxide with vegetable powder as a low-toxicity catalyst
-
This paper describes the scope and limitation of substrates subjected to asymmetric amination with epoxides catalyzed by a soluble soybean polysaccharide (Soyafibe S-DN), which we recently discovered from the reaction of 1,2-epoxycyclohexane with cyclopropylamine. Various meso-epoxides reacted with various amines afforded the corresponding products with good enantiomeric selectivity. Since it was found that pectin was found to have a catalytic ability after screening commercially available polysaccharides, we studied 33 different vegetable powders having pectic substances, and we found that many vegetable powders showed catalytic ability. These results should guide in using vegetable components as low-toxic catalysts for the production of pharmaceuticals.
- Asano, Tatsuhiro,Kurata, Hiroyuki,Takeuchi, Yuki,Tsuzaki, Kazuya,Wada, Koichi
-
-
- Catalytic asymmetric amination of meso-epoxide using soy polysaccharide (Soyafibe S-DN)
-
The asymmetric amination of epoxides is an effective method to synthesize chiral β-aminoalcohols and their components as pharmaceuticals. We have developed a new catalyst system for the asymmetric amination of 1,2-epoxycyclohexane with cyclopropylamine. We have also found that water-soluble soy polysaccharide (Soyafibe S-DN) functions as a catalyst. This catalytic reaction proceeded under mild conditions in hydrous toluene at 3740°C. (1R,2R)-2-(cyclopropylamino)-cyclohexan-1-ol was obtained at 64% enantiomeric excess (ee) by the asymmetric amination of 1,2-epoxycyclohexane with cyclopropylamine using this catalyst system; it was also made at >99% ee by purification as the fumarate salt. The catalytic activity of this soluble soy polysaccharide remained unchanged, even when treated with a protease, but its activity disappeared when treated with a sugar chain degrading enzyme. These results indicate that the polysaccharide rather than the protein acts as the catalyst for this reaction. Thus, we have discovered for the first time that polysaccharides can act as asymmetric catalysts for the amination of 1,2-epoxycyclohexane.
- Takeuchi, Yuki,Asano, Tatsuhiro,Tsuzaki, Kazuya,Wada, Koichi
-
p. 678 - 683
(2018/04/20)
-
- 2(1H)-Quinolinone derivatives as novel anti-arteriostenotic agents showing anti-thrombotic and anti-hyperplastic activities
-
In order to search for anti-arteriostenotic agents, a series of 2(1H)- quinolinone derivatives was synthesized and evaluated for anti-thrombotic activity and for anti-hyperplastic activity. From this series, (-)-6-[3-[3- cyclopropyl-3-[(1R,2R)-2-hydroxycycyclohexyl]ureido]propoxy]-2(1H)- quinolinone (1p, OPC-33509) was selected as the best candidate by balancing the efficacy on anti-thrombosis and anti-hyperplasia.
- Koga, Yasuo,Kihara, Yoshito,Okada, Minoru,Inoue, Yoshihiro,Tochizawa, Shirou,Toga, Kazuyuki,Tachibana, Kazue,Kimura, Yukio,Nishi, Takao,Hidaka, Hiroyoshi
-
p. 1471 - 1476
(2007/10/03)
-