Chiral Bifunctional Reagents for 1,3-Functionalization

University Of Texas At San Antonio, San Antonio TX

Investigators

Abstract

In this project funded by the Chemical Synthesis Program of the Chemistry Division, Prof. Hyunsoo Han of the University of Texas at San Antonio is developing new bifunctional reagents for the synthesis of complex organic compounds. These bifunctional reagents work without relying on functional group adjustments or on the use of protecting groups (two chief culprits of synthetic inefficiency), while maintaining high selectivity. Consequently, the prospective bifunctional reagents and accompanying synthetic strategies provide a versatile tool box for efficient asymmetric synthesis of many chemically and biologically important compounds, including natural products and pharmaceuticals. This occurs within the context of an emerging program for the training of young scientists in the Department of Chemistry at the University of Texas at San Antonio. The development of methods for carrying out two fundamental organic reactions, asymmetric aldehyde allylation/crotylation and allylic substitution/Michael addition, without functional group manipulations and protection groups is a main focus of this project. These targets include: (1) concise synthetic routes for bifunctional reagents; (2) extension of bifunctional reagents in the aldehyde allylation/crotylation reactions to a diverse array of aliphatic and aromatic aldehydes; (3) demonstration of the power and versatility of the synthetic strategies in the efficient asymmetric syntheses of 2-alkyl-1,3-diols/aminoalcohols as well as more complex and heretofore inaccessible ring systems. In contrast to more traditional B-, Si-, and/or Sn-based reagents, these bifunctional reagents operate through [3,3]-sigmatropic rearrangement under either acidic or oxidative conditions, and are totally "organic" (all C-based), making them environmentally benign and air-stable.