Highly Efficient Photochemically Induced Thiyl Radical-Mediated Racemization of Aliphatic Amines at 30 °C
作者:Lucie Routaboul、Nicolas Vanthuyne、Stéphane Gastaldi、Gérard Gil、Michèle Bertrand
DOI:10.1021/jo702241y
日期:2008.1.1
performance of highly efficient aliphatic amines racemization, under mild conditions at 30 °C. The reaction proceeds via the reversible generation of prochiral α-aminoalkyl radicals. The latter may result either from a redox process between the thiyl radical and the amine or from direct hydrogen atom abstraction by thiyl radical. As hydrogen atom donor, the thiol plays a crucial role. While the racemization
在30°C的温和条件下,在硫醇的存在下进行UV辐照可实现高效脂肪族胺的消旋化。该反应通过前手性α-氨基烷基自由基的可逆生成而进行。后者可能是由于噻吩基和胺之间的氧化还原过程或由噻吩基直接提取氢原子引起的。作为氢原子供体,硫醇起着至关重要的作用。虽然伯胺和仲胺的外消旋都是快速的过程,但叔胺的外消旋却很缓慢。暂定原理是基于光刺激的胺催化的硫醇氧化成相应的二硫化物,这使得反应介质中氢原子供体的浓度以取决于胺的性质的速率下降至痕量。