Recently, groundbreaking progress has been made in the field of chiral biphenyl compound synthesis. A research team has developed a novel asymmetric catalytic process that achieves highly precise enantioselectivity as high as 99.9%. This innovative method relies on a synergistic catalytic system combining an iridium-chiral bridged biphenyl phosphoramidite ligand with triethylborane, enabling the construction of a seven-membered oxazepine ring via an intramolecular allylic etherification reaction. Experimental results demonstrate that, under mild reaction conditions, weakly nucleophilic pyrimidine methanol substrates can be efficiently converted into the desired product with nearly quantitative yields (99%) and enantioselectivities surpassing the industry benchmark, reaching over 99.5%.

The core of the technology lies in the innovative design of chiral ligands, where the bridged biphenyl scaffold achieves precise control over the reaction transition state through a dual modulation mechanism—combining steric hindrance with electronic effects. Compared to conventional binaphthyl-based ligands, this system demonstrates remarkable advantages in stereoselective control, and the resulting products can be further transformed into highly functionalized derivatives. By systematically optimizing reaction parameters, the research team successfully scaled up the catalytic system to gram-level production while maintaining enantioselectivity above 99%, thereby validating its industrial-scale potential.

This achievement provides an efficient synthesis route for a key intermediate used in chiral pharmaceuticals, liquid crystal materials, and asymmetric catalysis. Its groundbreaking aspect lies in simultaneously achieving both ultra-high enantioselectivity and scalable processability, marking a significant leap forward in the technology of chiral biphenyl compound synthesis.