Synthesis of Amines and Amino Alcohols by Electrophilic Amination and Highly Stereoselective Reduction

✍ Scribed by Gmeiner, Peter ;Bollinger, Bernd

• Publisher: John Wiley and Sons
• Year: 1992
• Tongue: English
• Weight: 570 KB
• Volume: 1992
• Category: Article
• ISSN: 0947-3440
• DOI: 10.1002/jlac.199219920147

✦ Synopsis

Abstract

A practical and selective method for the synthesis of the β‐arylamines 5 and the cis‐ or trans‐amino alcohols 8 or 11 is reported. The reaction sequence starts from α‐tetralones 1 which readily react with dibenzyl azodicarboxylate to afford the protected α‐hydrazino ketones 2. Then, depending on the reduction conditions, the trans‐hydrazino alcohols 10 or the cis isomers 7 are formed predominantly. The stereoselectivities which range between 18:1 and 1:67 (trans/cis) are explained by stereoelectronic effects (σ,σ interactions) and steric hindrance. Depending on the workup procedure, we can control, whether the cis‐hydrazino alcohols 7 or the oxazolidinone derivatives 3 are isolated. Subsequent hydrogenolyses of 4, 7 and 10 lead to the target molecules 5, 8 and 11, respectively.