Amino Acid-Based Reoxidants for Aminohydroxylation: Application to the Construction of Amino Acid-Amino Alcohol Conjugates

摘要

In recent years, there has been a surge in reports of methodology aimed at synthesizing the 1,2-amino alcohol motif. Despite numerous studies, this key unit is still highly sought after because of its occurrence in many different organic compounds of value ranging from natural products to pharmaceutical agents. Methods that allow for the regioselective and stereospecific addition of nitrogen and oxygen across a double bond are rare, and continue to be influenced by the osmium-catalysed aminohydroxylation reaction. Recent developments of this reaction have witnessed the introduction of N-O based reoxidants for osmium that have made the process much more reliable and high-yielding. Herein, we report for the first time the use of natural amino acids as a scaffold for such reoxidants, allowing their conjugation with alkenes in a regio- and stereocontrolled process. This sequence enables rapid access to well-defined and enantiopure amino alcohols using a transition metal and a chiral ligand in catalytic amounts.