Quaternary Stereogenic Carbon Atoms in Complex Molecules by an Asymmetric, Organocatalytic, Triple-Cascade Reaction

摘要

The stereoselective construction of all-carbon quaternary sterogenic centers in complex organic molecules is an ongoing synthetic challenge.[1] This is due to the growing number of biologically active natural products and pharmaceutical agents that possess quaternary stereogenic carbons. However, creating these complex fragments rapidly and selectively is a difficult task, because of the inherent steric bias encountered in the C-C bond-forming event. In this field, enantioselective cascade catalysis has been recognized as a new synthetic solution to the stereoselective construction of molecular complexity.[2] This bio-inspired strategy is based upon the combination of multiple asymmetric transformations in a cascade sequence, providing rapid access to complex molecules containing multiple stereocenters from simple precursors and in a single operation.