Toyoharu Miyagawa

Synthesis and optical resolution of a Cu(I) double-stranded helicate with ketimine-bridged tris(bipyridine) ligands

A tetranuclear Cu(I) double-stranded helicate was synthesized from ketimine-bridged tris(bipyridine) ligands and Cu(I) ions, and the racemate was successfully resolved by diastereomeric salt formation using an optically pure phosphate anion followed by anion exchange with NaPF(6) without racemization.

Synthesis and radical ring‐opening polymerization of 1‐phenyl‐2‐vinylcyclopropane in the presence of TEMPO

Synthesis and radical ring-opening polymerization behavior of 1-phenyl-2-vinylcyclopropane (PhVCP) were examined. PhVCP was synthesized by the coupling reaction of butadiene with phenyldiazomethane, where cis and trans isomers were obtained with the ratio 78 : 22. Radical polymerization of PhVCP was carried out in bulk at 60–180°C with 2,2′-azoisobutyronitrile, benzoyl peroxide, or di-tert-butyl peroxide as initiator to obtain a 1,5-ring-opened polymer with Mn ≈ 1 900. When PhVCP was polymerized in the presence of 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO), Mn of the obtained polymer increased with time. The radical polymerizability of PhVCP is much lower compared with that of styrene. From the molecular-orbital calculation of both monomers, it has been suggested that this is not caused by an electronic factor of the vinyl group but by side reactions such as the abstraction of a hydrogen atom from the allylic position of PhVCP.