Center for Integrated Nanostructure Physics

The introduction of chirality into biomolecular systems has been a fascinating issue for a long time. Usually, terrestrial life utilizes only the L-enantiomer of amino acids, a pattern that is known as the ‘homochirality of life’. Until now, the chiral small molecues can be obtained enantioselectively only if chiral reactants, chiral catalysts, chiral substrates, or chiral auxiliaries are involved or if polymers with some external chiral influence are present. However, there is almost no report to make chiral monomers without using a chiral auxiliary. To have 'one enantiomer' out of two mirror images in molecules and complexes is one of our primary goals without using any chiral agents.

To break this limit, we like to introduce a circularly polarized light (CPL) to prepare one handedness helicity or enantiomeric excess of small molecules, complexes, and even nanoparticles. Up-to date, no one has reported the CPL as a chiral source for making any chiral monomers, which is one of the ground-breaking challenges all over the world. For the first time, we propose that only rotational direction of CPL can induce the chirality. It is very exciting to generate the chiral monomers with CPL for various applications in many different fields.

We are currently focusing on finding the possibility for the synthesis of one handedness helicity or enantiomeric excess for various chiral monomers by using only CPL system as shown below;

• Enantiospecific photocylisation of diarylethene for opto-electronics such as photo-switches and smart sensors

• Stereo-specific Diels-Alder reactions for bio-active derivatives

• Enantio-selective thiol-ene reactions for enantiomeric pure amino acids

• Asymmetric synthesis of small organic molecules

▲ Figure. Scheme of the possible prepration of one handedness helicity or enantiomeric excess monomers using CPL