A Versatile Ru Catalyst for the Asymmetric Transfer Hydrogenation of Both Aromatic and Aliphatic Sulfinylimines
作者:Óscar Pablo、David Guijarro、Gábor Kovács、Agustí Lledós、Gregori Ujaque、Miguel Yus
DOI:10.1002/chem.201102426
日期:2012.2.13
A highly efficient Ru catalyst based on an achiral, very simple, and inexpensive amino alcohol ligand (2‐amino‐2‐methylpropan‐1‐ol) has been developed for the asymmetric transfer hydrogenation (ATH) of chiral N‐(tert‐butylsulfinyl)imines. This complex is able to catalyze the ATH of both aromatic and the most challenging aliphatic sulfinylimines by using isopropyl alcohol as the hydrogen source. The
已开发出一种基于非手性,非常简单且廉价的氨基醇配体(2-氨基-2-甲基丙烷-1-醇)的高效Ru催化剂,用于手性N-(叔丁基亚磺酰基)的不对称转移氢化(ATH))。通过使用异丙醇作为氢源,该络合物能够催化芳香族和最具挑战性的脂肪族亚磺酰亚胺的ATH。在短反应时间内(1-4小时)对芳香,杂芳和脂肪族亚磺酰基酮亚胺进行非对映选择性还原,包括空间拥塞的情况,然后对氮原子进行脱亚磺酰化,得到相应的高度对映体富集的(ee高达99%以上)的α支链伯胺,收率很高。通过在亚胺基体中使用适当的绝对构型,相同的配体对于(R)和(S)胺的合成同样有效。DFT机理研究表明,氢转移过程是逐步进行的。此外,非对映选择性的起源已被合理化。