Ligand-enabled cross-coupling of C(sp3)-H bonds with arylboron reagents via Pd(II)/Pd(o) catalysis
Ligand-enabled cross-coupling of C(sp3)-H bonds with arylboron reagents via Pd(II)/Pd(o) catalysis
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DOI：
10.1038/nchem.1836
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发表时间：
2014-02-01
期刊：
影响因子：
21.8
通讯作者：
Yu, Jin-Quan
中科院分区：
文献类型：
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作者：
Chan, Kelvin S. L.;Wasa, Masayuki;Yu, Jin-Quan
在过去的十年中，C-H活化反应取得了许多进展。被表面上不反应的C-H键上的分子直接官能化的能力所吸引，化学家们已经发现了使C(sp(2))-H和C(sp(3))-H键与各种偶联伙伴反应的反应条件。尽管取得了这些进展，但开发能够催化C(sp(3))-H键官能化的合适的配体仍然是一个巨大的挑战。在这里，我们报告了一种单N保护的氨基酸配体的发现，该配体能够使Pd(II)催化三氟保护的胺中的Gamma-C(sp(3))-H键与芳基硼试剂偶联。值得注意的是，在没有配体的情况下，没有观察到本底反应。用该方法对多种胺底物和芳基硼试剂进行了交叉偶联。氨基酸衍生的光学活性底物的芳基化也为制备非蛋白生成氨基酸提供了一条潜在的途径。
There have been numerous developments in C-H activation reactions in the past decade. Attracted by the ability to functionalize molecules directly at ostensibly unreactive C-H bonds, chemists have discovered reaction conditions that enable reactions of C(sp(2))-H and C(sp(3))-H bonds with a variety of coupling partners. Despite these advances, the development of suitable ligands that enable catalytic C(sp(3))-H bond functionalization remains a significant challenge. Herein we report the discovery of a mono-N-protected amino acid ligand that enables Pd(II)-catalysed coupling of gamma-C(sp(3))-H bonds in triflyl-protected amines with arylboron reagents. Remarkably, no background reaction was observed in the absence of ligand. A variety of amine substrates and arylboron reagents were cross-coupled using this method. Arylation of optically active substrates derived from amino acids also provides a potential route for preparing non-proteinogenic amino acids.