Synthesis and characterization of naphthalimide-functionalized polynorbornenes

ABSTRACT: Highly fluorescent and photostable (2-alkyl)-1H-benzo[de]isoquinoline-1,3(2H)-diones with a polymerizable norbornene scaffold have been synthesized and polymerized using ring-opening metathesis polymerization. The monomers presented herein could be polymerized in a living fashion, using different comonomers and different monomer ratios. All obtained materials showed good film-forming properties and bright fluorescence caused by the incorporated push–pull chromophores. Additionally, one of the monomers containing a methylpiperazine functionality showed protonation-dependent photoinduced electron transfer which opens up interesting applications for logic gates and sensing. GRAPHICAL ABSTRACT: [Image: see text

Dynamic Kinetic Resolution of 2-Phenylpropanal Derivatives to Yield β-Chiral Primary Amines via Bioamination

The amination of racemic alpha-chiral aldehydes, 2-phenylpropanal derivatives, was investigated employing omega-transaminases. By medium and substrate engineering the optical purity of the resulting β-chiral chiral amine could be enhanced to reach optical purities up to 99% ee. Using enantiocomplementary w-transaminases allowed us to access the (R)- as well as the (S)-enantiomer in most cases. It is important to note that the stereopreference of the omega-transaminases found for alpha-chiral aldehydes did not correlate with the stereopreference previously observed for the amination of methyl ketones. In one case the stereopreference switched even upon exchanging a methyl substituent to a methoxy group