The Ryu Research Group, Department of Chemistry, Graduate School of Science, Osaka Prefecture University

Osaka Prefecture University School of Science  Department of Chemistry  Access  Sitemap


Published in 2009

Addition of allyl bromide to phenylacetylene catalyzed by palladium on alumina and its application to a continuous flow synthesis
Fukuyama, T., Kippo, T., Ryu, I., Sagae, T.
Research on Chemical Intermediates, 2009, 35, pp. 1053 - 1057
DOI: 10.1007/s11164-009-0069-x

The reaction of allyl bromide with phenylacetylene catalyzed by Pd/Al2O3 pellets and Pd/C powder was investigated. Bromoallylation of phenylacetylene took place to give a regioisomeric mixture of 1-bromo-substituted 1,4-dienes. The bromoallylation of phenylacetylene was successfully applied to a continuous flow synthesis using a stainless steel made column packed with Pd/Al2O3 pellets.

Hydroruthenation triggered catalytic conversion of dialdehydes and keto aldehydes to lactones
Omura, S., Fukuyama, T., Murakami, Y., Okamoto, H., Ryu, I.
Chemical Communications, 2009, 44, pp. 6741 - 6743
DOI: 10.1039/B912850F

Lactonization of dialdehydes and keto aldehydes was effectively catalyzed by RuHCl(CO)(PPh3)3. A cascade lactonization sequence accompanied by cross-coupling with enones was also attained.

An automated-flow microreactor system for quick optimization and production: application of 10-and 100-gram order productions of a matrix metalloproteinase inhibitor using a Sonogashira coupling reaction
Sugimoto, A., Fukuyama, T., Rahman, M. T., Ryu, I.
Tetrahedron Lett. , 2009, 50, pp. 6364 - 6367
DOI: 10.1016/j.tetlet.2009.08.089

Sonogashira coupling reaction leading to a matrix metalloproteinase inhibitor was investigated using an automated microreactor system, which is a sequential temperature- and flow rate-programed reaction evaluation system. By repeating the use of this computer-controlled system four times, we were able to determine the optimal conditions and quickly apply them to a 10 g scale synthesis using the same microreactor system. The optimal conditions were also applied to a 100 g scale production by using another microflow system composed of a T-shaped micromixer (200 μm id) and a stainless tube reactor (2000 μm id and 20 m length). Total time spent for both optimization and production was as short as 50 h.

Organocatalytic Enantioselective Synthesis of Nitrogen-Substituted Dihydropyran-2-ones, a Key Synthetic Intermediate of 1 beta-Methylcarbapenems
Kobayashi, S., Kinoshita, T., Uehara, H., Sudo, T., Ryu, I.
Org. Lett., 2009, 11, pp. 3934 - 3937
DOI: 10.1021/ol901544q

Organocatalytic enantioselective cycloadditions providing nitrogen-substituted dihydropyran-2-ones were developed in two catalytic systems. The (3R,4R)-product was a versatile intermediate in the synthesis of 1β-methylcarbapenem antibiotics.

Microflow Radical Carboaminoxylations with a Novel Alkoxyamine
Wienhoefer, I. C., Studer, A., Rahahman, M. D., Fukuyama, T., Ryu, I.
Org. Lett., 2009, 11, 11 pp. 2457 - 2460
DOI: 10.1021/ol900713d

Highly efficient thermal radical carboaminoxylations of various olefins by using the novel alkoxyamine A to give adducts of type B are described. It is reported that these radical addition reactions can be performed in a microflow reaction system. As compared to conventional batch reaction setup, significantly higher yields are obtained by running carboaminoxylations using the microflow system under analogous conditions.

Microflow photo-radical reaction using a compact light source: application to the Barton reaction leading to a key intermediate for myriceric acid A
Sugimoto, A., Fukuyama, T., Sumino, Y., Takagi, M., Ryu, I.
Tetrahedron, 2009, 65, 8 pp. 1593 - 1598
DOI: 10.1016/j.tet.2008.12.063

The Barton reaction (nitrite photolysis) of a steroidal substrate 1, to give 2, a key intermediate for the synthesis of myriceric acid A, an endothelin receptor antagonist, was successfully carried out in a continuous microflow system using a Pyrex glass-covered stainless-steel microreactor having a one lane microchannel (Type A: 1000 μm width, 107 μm depth, 2.2 m length). We found that using a low-power black light (peak wavelength: 352 nm) and UV-LED light (peak wavelength: 365 nm) as the light source will suffice for the Barton reaction, creating a compact energy-saving photo-microreaction system. A multi-gram-scale production was attained using a multi-lane microreactor (Type B: 1000 μm width, 500 μm depth, 0.5 m length, 16 lanes) in conjunction with a black light.



Laboratory for Advanced Organic Synthesis
Organization for Research Promotion Osaka Prefecture University
Sakai, Osaka 599-8531, JAPAN
Mail:ryu --at-- Replace @ instead of  "--at--".