Ligand-controlled C(sp³)-H arylation and olefination in synthesis of unnatural chiral ?-amino acids.

ABSTRACT: The use of ligands to tune the reactivity and selectivity of transition metal catalysts for C(sp(3))-H bond functionalization is a central challenge in synthetic organic chemistry. Herein, we report a rare example of catalyst-controlled C(sp(3))-H arylation using pyridine and quinoline derivatives: The former promotes exclusive monoarylation, whereas the latter activates the catalyst further to achieve diarylation. Successive application of these ligands enables the sequential diarylation of a methyl group in an alanine derivative with two different aryl iodides, affording a wide range of ?-Ar-?-Ar'-?-amino acids with excellent levels of diastereoselectivity (diastereomeric ratio > 20:1). Both configurations of the ?-chiral center can be accessed by choosing the order in which the aryl groups are installed. The use of a quinoline derivative as a ligand also enables C(sp(3))-H olefination of a protected alanine.

SUBMITTER: He J 

PROVIDER: S-EPMC4179246 | biostudies-literature | 2014 Mar

REPOSITORIES: biostudies-literature