Prof. Jaesook Yun’s Research Team Developed Enantioselective Carbon-carbon Conjugate Addition Using Olefin

- developed asymmetric alkylation reaction of alkenes using chiral catalyst

SKKU (President Dong-Ryeol Shin) is pleased to announce that Prof. Jaesook Yun’s research team from the Department of Chemistry developed an effective synthesis method of chiral alkylboron compounds through transition metal catalysis.

The chiral alklyboron compounds are a very useful synthetic intermediary used in various fields such as natural products, medicines, and functional materials, and has received much attention not only from academia but also from the industry. Despite several important research advances have been made in this research field, the conjugate addition with a chiral secondary alkyl metal nucleophile for the C−C bond formation with two contiguous stereogenic centers has been rarely reported and represents an enormous challenge.

The team developed a CuH‐catalyzed asymmetric reductive conjugate addition of borylalkenes to α,β‐unsaturated diesters with high chemo‐, diastereo‐, and enantioselectivity. This method provides efficient and direct access to enantioenriched alkylboron compounds carrying two contiguous stereogenic centers by assembling readily available starting alkenyl reagents in a single operation without using preformed organometallic reagents or chiral auxiliaries, which greatly expands the scope of asymmetric conjugate addition. It was the first case of asymmetric conjugate addition of chiral secondary alkyl, allowing for high yield and selective synthesis of chiral alkylboron compounds with continuous stereogenic centers, which were previously inaccessible.

Moreover, the utility of the resulting products was demonstrated in the efficient synthesis of (−)‐phaseolinic acid and other derivatives. Efforts to expand the use of other chiral alkylcopper species in the asymmetric conjugate addition are currently underway. It is expected to be a very useful synthesis tool for synthesizing bones of important medicines and physiological active substances.

The first author, Dr. Won-jun Jang, conducted this study when he was a pos doc student at SKKU. He is currently serving as a post-doctoral researcher at the University of Chicago Guangbin Dong Group through the “2020 Post-doctoral Training” program organized by National Research Foundation of Korea.

This work was supported by Samsung Science and Technology Foundation under Project Number SSTF‐BA2002‐08 and was published in the world-renowned journal, ‘Angewandte Chemie International Edition (ACIE; IF=12.959)’ on February 23 (Tue).

* Paper: Asymmetric Conjugate Addition of Chiral Secondary Borylalkyl Copper Species