1582807-13-3Relevant academic research and scientific papers
LIGAND-CONTROLLED C(SP3)-H ARYLATION AND OLEFINATION IN SYNTHESIS OF UNNATURAL CHIRAL ALPHA AMINO ACIDS
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Page/Page column 121-124; 126; 127, (2015/10/05)
The use of ligands to tune the reactivity and selectivity of transition metal-catalysts for C(-sp3)-H bond functionalization is a central challenge in synthetic organic chemistry. Herein, we report a rare example of catalyst-controlled C(sp3)-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 β-Ar-p-Ar ' -cc-amino acids with excellent levels of diastereoselectivity (d.r. > 20:1). Both configurations of the β-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(sp3)-H olefination of a protected alanine.
Ligand-controlled C(sp3)-H arylation and olefination in synthesis of unnatural chiral α-amino acids
He, Jian,Li, Suhua,Deng, Youqian,Fu, Haiyan,Laforteza, Brian N.,Spangler, Jillian E.,Homs, Anna,Yu, Jin-Quan
, p. 1216 - 1220 (2014/04/03)
The use of ligands to tune the reactivity and selectivity of transition metal catalysts for C(sp3)-H bond functionalization is a central challenge in synthetic organic chemistry. Herein, we report a rare example of catalyst-controlled C(sp3)-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 β-Ar-β-Ar?-α-amino acids with excellent levels of diastereoselectivity (diastereomeric ratio > 20:1). Both configurations of the β-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(sp3)-H olefination of a protected alanine.
