Enantioselective Hydrogenation of Activated Aryl Imines Catalyzed by an Iron(II) P-NH-P′ Complex
作者:Chris S. G. Seo、Thibault Tannoux、Samantha A. M. Smith、Alan J. Lough、Robert H. Morris
DOI:10.1021/acs.joc.9b01964
日期:2019.9.20
industries. Asymmetric imine hydrogenation, particularly with iridium catalysts, is well developed. However, imine reduction still remains challenging in the context of replacing such a precious metal with a cheap, nontoxic, and environmentally friendly substitute such as iron. Here, we report that an unsymmetrical iron P-NH-P′ catalyst that was previously shown to be effective for the asymmetric hydrogenation
手性胺是合成化学的关键组成部分,在农业和制药工业中有许多应用。不对称的亚胺氢化,特别是使用铱催化剂的氢化,已经得到了很好的发展。但是,在用廉价,无毒且环保的替代品(例如铁)替代这种贵金属的背景下,还原亚胺仍然具有挑战性。在这里,我们报道先前被证明对芳基酮的不对称氢化有效的不对称铁P-NH-P'催化剂,对于被N-二苯基膦酰基或N活化的前手性芳基亚胺的不对称氢化也是非常有效的催化剂。-甲苯磺酰基。P-NH-P'的缩写表示(S,S)-PPh 2CHPhCHPhNHCH 2 CH 2 P i Pr 2。密度泛函理论结果表明,出人意料的是,与亚胺氮本身相反,催化剂上的NH基团通过与亚胺氮上的PO或SO基的氢键键合而使亚胺受氢化物的攻击而活化。这可以解释为什么N -Ph和N- Bu亚胺不被氢化。