[EN] LIGAND-CONTROLLED C(SP3)-H ARYLATION AND OLEFINATION IN SYNTHESIS OF UNNATURAL CHIRAL ALPHA AMINO ACIDS<br/>[FR] ARYLATION COMMANDÉE PAR LIGAND DE C(SP3)-H ET OLÉFINATION UTILISABLES DANS LE CADRE DE LA SYNTHÈSE D'ACIDES ALPHA-AMINÉS CHIRAUX NON NATURELS
申请人:SCRIPPS RESEARCH INST
公开号:WO2015131100A1
公开(公告)日:2015-09-03
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-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.
使用配体调节过渡金属催化剂对C(-sp3)-H键官能化的反应性和选择性是合成有机化学中的一个核心挑战。在这里,我们报告了一个罕见的催化剂控制的C(sp3)-H芳基化的例子,使用吡啶和喹啉衍生物:前者促进了独特的单芳基化,而后者进一步激活了催化剂以实现二芳基化。这些配体的连续应用使得在丙氨酸衍生物中的甲基基团上进行顺序二芳基化成为可能,使用两种不同的芳基碘化物,得到了一系列具有优异立体选择性的β-Ar-p-Ar' -cc-氨基酸(d.r. > 20:1)。通过选择芳基基团的安装顺序,可以访问β-手性中心的两种构型。使用喹啉衍生物作为配体还可以实现保护丙氨酸的C(sp3)-H烯烃化。