Polyionic polymers – heterogeneous media for metal nanoparticles as catalyst in Suzuki–Miyaura and Heck–Mizoroki reactions under flow conditions

• Klaas Mennecke and
• Andreas Kirschning

Beilstein J. Org. Chem. 2009, 5, No. 21, doi:10.3762/bjoc.5.21

• heterogenization of transition metals. A major hurdle for industrial applications of heterogenized homogeneous metal catalyst is associated with keeping metal leaching down to a minimum. Immobilization can be regarded as one enabling technique in organic chemistry [5][6] that in conjunction with continuous flow

• processes creates an ideal setup for an automated solution-phase synthesis. Furthermore, this combination of enabling techniques has great potential in the production of fine chemicals [7][8]. In continuation of our efforts in developing immobilization concepts for reagents and catalysts including

Asymmetric reactions in continuous flow

• Xiao Yin Mak,
• Paola Laurino and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2009, 5, No. 19, doi:10.3762/bjoc.5.19

• of asymmetric synthesis using solid-supported catalysts is the development of an immobilization strategy that maintains both good stereoselectivity and catalyst activity. Selectivities obtained using homogeneous catalysts that work well in solution phase can often be significantly reduced when

A biphasic oxidation of alcohols to aldehydes and ketones using a simplified packed- bed microreactor

• Andrew Bogdan and
• D. Tyler McQuade

Beilstein J. Org. Chem. 2009, 5, No. 17, doi:10.3762/bjoc.5.17

• liquids [38] have been extensively studied and are useful because the oxidation conditions are mild, selective, and the catalysts do not require regeneration. TEMPO, however, is expensive and difficult to remove from reaction mixtures. For these reasons, TEMPO immobilization is an important goal because

• it enables facile removal and recycling. We recently reported the development of an effective solid support for use in packed-bed microreactors [39], AMBERZYME® Oxirane (AO, 1), a commercially available resin with pendant epoxide functionalities designed for enzyme immobilization. AO is readily

• functionalized with a range of catalysts and works well as packing material for flow chemistry [39]. In this report, we demonstrate the immobilization of TEMPO and its use in a flow system using the Anelli-Montanari protocol for the oxidation of primary and secondary alcohols [30][40]. Our simplified reactor is

The first salen- type ligands derived from 3',5'-diamino- 3',5'-dideoxythymidine and -dideoxyxylothymidine and their corresponding copper(II) complexes

• Daniel Koth,
• Michael Gottschaldt,
• Helmar Görls and
• Karolin Pohle

Beilstein J. Org. Chem. 2006, 2, No. 17, doi:10.1186/1860-5397-2-17

• as the replacement of the thymine base by different functional groups or the immobilization of the complexes by the nucleobase enables the resulting complexes to become promising candidates as catalysts for enantioselective reactions. Conclusion In summary, an effective route for the synthesis of 3