#Organocatalyst that controls radical reactions for complex and bulky compound synthesis

The key to this success was their finding that the N-neopentyl group of the thiazolium-type N-heterocyclic carbene was effective in the reaction progress, while their study was carried out making full use of organic chemistry and measurement techniques. The bulkiness of the N-neopentyl group was found to be effective not only in promoting a coupling reaction of two different radical species generated in the reaction system but also in suppressing undesirable side reactions.

The present catalytic reaction has the following merits in organic chemical synthesis; 1) bulky molecules can be reaction substrates due to involvement of a highly reactive radical, and 2) the method is excellent in terms of a wide range of functional groups and substrates, since the catalytic reaction can be carried out under mild conditions without the need for metal catalysts or redox reagents. Thus, it is now possible to synthesize more than 35 bulky and complex dialkyl ketones, which was previously very difficult. This enables the synthesis of natural compounds and pharmaceuticals having a dialkyl ketone backbone from an aliphatic aldehyde and an aliphatic carboxylic acid derivative.
In this study, the research group has designed a new organocatalyst that controls radical reactions, which significantly widens the applicability to various substrates. The study is expected to accelerate drug discovery, since it enables synthesis of organic compounds with high added value that used to be nearly impossible to attain. From an academic viewpoint, the study has established design guidelines of organocatalysts that can control radical reactions.