KOSEN 한인과학기술자네트워크

1. DKR (Dynamic Kinetic Resolution)

    The dynamic kinetic resolution (DKR) is a promising strategy to overcome the limitation of kinetic resolution (KR) for the synthesis of optically pure compounds from racemic mixtures, in which racemization and kinetic resolution proceed in a single reaction vessel

. For the successful DKR efficient catalysts for the racemization of substrates are required. We have been developing catalysts for the racemization of alcohols and amines

2. Metal Nanoparticle Catalysts

    In contrast to bulk metals, nano-size metal particles show interesting and characteristic activities in valuable organic transformations. Recently, we have developed a simple method that can provide heterogeneous catalysts containing metal nanoparticles (Pd, Rh, Ir, Pt, Ru, Cu, Au, etc.) <Figure 1>. We are developing new metal nanoparticle catalysts and organic transformations using them <Figure 2>.

3. Imine Chemistry

Imines have been recognized as pivotal intermediates in organic synthesis, particularly for the preparation of nitrogencontaining bioactive natural products and derivatives. Compared with carbonyl groups, imines are more difficult to handle because of their chemically labile nature.As a result of this problem, the transformation into the amine products usually employs imines possessing a substituent on the nitrogen atom (N-substituted imines). However, from a synthetic viewpoint this protocol necessitates removal of the substituent to access the amine products. In this regard, the use of N-unsubstituted imines would be ideal in that the elimination step is not necessary.

we report that Nunsubstituted imines can be efficiently generated using 1 and the structurally related ruthenium complex 2 Remarkably, the mild reaction conditions used in this transformation even allowed the observation of cis/trans isomers of the N-unsubstituted imines by NMR spectra taken at room temperature. Moreover, this new protocol enables various chemoselective transformations of N-unsubstituted imines.