The green chemistry method combines light and air to build key molecules for future drugs

A research group led by Osaka University has achieved a world first in catalytic asymmetric synthesis, developing an innovative method to efficiently produce NOBIN, a valuable molecule used in pharmaceuticals.

Their article “Enantioselective Heterocoupling of 2-Naphthylamines with 2-Naphthol Derivatives via Cooperative Photoactivation and Chiral Vanadium(V) Catalysis” was published in ACS catalysis.

Their approach combines a vanadium catalyst, LED light and oxygen, dramatically reducing waste by eliminating byproduct formation common with traditional methods and establishing a highly sustainable synthetic route.

Many modern drugs and functional materials are based on molecules that exist in “clockwise” and “left-handed” forms, so-called chiral molecules. Traditionally, producing these molecules requires multiple steps and often produces unwanted chemical waste.

In the case of NOBIN, previous methods always generated additional unwanted byproducts, reducing efficiency and increasing environmental impact.

The team's innovation lies in the cooperative combination of a vanadium catalyst and light. The catalyst selectively converts 2-naphthol into a radical species. At the same time, LED light produces a cationic radical species from 2-naphthylamine under oxygen via a charge transfer complex.

These two radicals then couple efficiently and yield exclusively NOBIN derivatives. This allows for an ideal input ratio of 1:1 of starting materials and uses low-energy LED light, which significantly minimizes environmental impact and makes the synthesis extremely sustainable.

This clean process only produces water as a byproduct, which represents exceptional environmental sustainability and waste reduction. Activating molecules using light is energy efficient and safe, accelerating next-generation asymmetric synthesis research.

Professor Shinobu Takizawa, senior author of the study, explains: “This achievement opens new avenues in chemical synthesis, with anticipated applications for more complex molecules and drug candidates. Cooperative catalysis, combining light and metal catalysts, embodies a sustainable chemical process. This study is an important step towards creating an ecologically harmonious one future society.”