Achiral β-amino alcohols as efficient ligands for the ruthenium-catalysed asymmetric transfer hydrogenation of sulfinylimines

✍ Scribed by David Guijarro; Óscar Pablo; Miguel Yus

• Publisher: Elsevier Science
• Year: 2011
• Tongue: French
• Weight: 208 KB
• Volume: 52
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/j.tetlet.2010.12.031

✦ Synopsis

Some achiral b-amino alcohols have been shown as efficient ligands for the ruthenium-catalysed asymmetric transfer hydrogenation of N-(tert-butylsulfinyl)imines in isopropanol. The ruthenium complex prepared from [RuCl 2 (p-cymene)] 2 (2.5 mol %) and 2-amino-2-methyl-1-propanol (5 mol %) leads to a-branched chiral primary amines with very high optical purities (up to 98% ee) by the diastereoselective reduction of the imines followed by removal of the sulfinyl group under mild acidic conditions. Short reaction times (2-3 h) were needed to complete the reduction reactions when they were performed at 50 °C.