Development of Selective Molecular Transformations Based on Unique Chemical Properties of Silver Catalyst: A Theoretical Analysis and Experimental Verification

Abstract

Due to the recent remarkable progress in both theory and hardware, integrating computational analysis into experimental studies improves our understanding of observed phenomena and guides future project planning. In the discipline of synthetic organic chemistry, this two-way approach is a powerful tactic for the clever design of new reactions and transition-metal catalysis. Summarizing our recent achievement, we herein report the development of a methodology based on the unique chemical properties of silver catalyst. An asymmetric O-H insertion reaction into phenols using a chiral homobinuclear complex created in situ from AgNTf₂ and (S)-XylylBINAP is presented along with computational analysis. By taking advantage of the high electrophilicity of silver-carbenes, chemoselectivity and enantioselectivity were controlled in phenol dearomatization reactions. Site- and chemoselective C-H functionalization using nitrene species, i.e., an isoelectronic nitrogen analog of carbene species, were achieved, leading to the synthesis of an array of spiroaminals. The theoretical investigation supports the origin of the chemoselectivity and the composition of an elementary hydrogen transfer/radical recombination mechanism involving triplet ground states of silver-nitrene species. We end by describing our newly developed method for diazo-free generation of silver-carbene, and its application for the dearomatization of nonactivated arenes.