Sustainable and Chemoselective Synthesis of α-Aminonitriles Using Lewis and Brønsted Acid-Functionalized Nanoconfined Spaces.

Abstract

α-Aminonitriles are significant components in the synthesis of biological compounds and complex drugs. Although efficient, procedures for synthesizing α-aminonitriles suffer from high loadings of expensive catalysts, long reaction times, energy-intensive conditions, and expensive, toxic solvents. Herein, we report the use of metal-organic framework Cr-MIL-101-SO3H as a catalyst for the facile synthesis of eight α-aminonitriles, five of which are reported as new molecules. We found that the presence of both open Cr3+ Lewis and -SO3H Brønsted acids in the MIL-101 pores is vital for the one-pot synthesis of α-aminonitriles. The catalytic reaction is conducted under solvent-free conditions at room temperature and a Cr-MIL-101-SO3H loading of 1% by the total mass, which is considered a sustainable synthetic pathway of α-aminonitriles. Additionally, we demonstrated for the first time that Cr-MIL-101-SO3H exhibits a high degree of catalytic chemoselectivity, differing substrates with sterically hindered and electronically withdrawn functional groups. Our study expands the existing family of α-aminonitriles and provides an intelligent strategy for the development of catalysts that can be used to synthesize functional α-aminonitriles with potential in therapeutics and health applications.