Shenzhen Key Laboratory of Small Molecule Drug Discovery and Synthesis, Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, Guangdong, China.
Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, Guangdong, China.
Org Biomol Chem. 2021 Oct 27;19(41):8934-8939. doi: 10.1039/d1ob01710a.
A series of half-sandwich Ir(III) complexes 1-6 bearing an amidato bidentate ligand were conveniently synthesized and applied to the catalytic Leuckart-Wallach reaction to produce racemic α-chiral primary amines. With 0.1 mol% of complex 1, a broad range of ketones, including aryl ketones, dialkyl ketones, cyclic ketones, α-keto acids, α-keto esters and diketones, could be transformed to their corresponding primary amines with moderate to excellent yields (40%-95%). Asymmetric transformation was also attempted with chiral Ir complexes 3-6, and 16% ee of the desired primary amine was obtained. Despite the unsatisfactory enantio-control achieved so far, the current exploration might stimulate more efforts towards the discovery of better chiral catalysts for this challenging but important transformation.
一系列的半夹心 Ir(III) 配合物 1-6 带有酰胺基双齿配体，很方便地被合成出来，并应用于催化 Leuckart-Wallach 反应，以生成外消旋的 α-手性伯胺。以 0.1 mol%的配合物 1，广泛的酮类，包括芳基酮、二烷基酮、环状酮、α-酮酸、α-酮酯和二酮，可以转化为相应的伯胺，产率中等至优秀（40%-95%）。手性 Ir 配合物 3-6 也进行了不对称转化，得到了所需伯胺的 16%ee。尽管目前的对映体控制还不尽如人意，但这种探索可能会激发更多的努力，以发现更好的手性催化剂，用于这一具有挑战性但重要的转化。
