Unusual NHC–Iridium(I) Complexes and Their Use in the Intramolecular Hydroamination of Unactivated Aminoalkenes
作者:Gellért Sipos、Arnold Ou、Brian W. Skelton、Laura Falivene、Luigi Cavallo、Reto Dorta
DOI:10.1002/chem.201600378
日期:2016.5.10
N‐heterocycliccarbene (NHC) ligands with naphthyl side chains were employed for the synthesis of unsaturated, yet isolable [(NHC)Ir(cod)]+ (cod=1,5‐cyclooctadiene) complexes. These compounds are stabilised by an interaction of the aromatic wingtip that leads to a sideways tilt of the NHC−Ir bond. Detailed studies show how the tilting of such N‐heterocycliccarbenes affects the electronic shielding
具有萘基侧链的N-杂环卡宾(NHC)配体用于合成不饱和但可分离的[(NHC)Ir(cod)] +(cod = 1,5-环辛二烯)配合物。这些化合物通过芳族翼尖的相互作用而稳定,从而导致NHC-Ir键的侧向倾斜。详细的研究表明,此类N杂环卡宾的倾斜如何影响卡宾碳原子的电子屏蔽性能,以及13 C NMR信号中的明显高场位移如何反映出这种情况。当用于分子内加氢胺化时,这些[(NHC)Ir(cod)] +在温和的反应条件下,这些物种显示出很高的催化活性。对映体纯的催化剂体系可产生具有出色对映选择性的吡咯烷。
Developing NHC-Iridium Catalysts for the Highly Efficient Enantioselective Intramolecular Hydroamination Reaction
introduced as catalysts for the intramolecular hydroamination reaction of unactivated aminoalkenes. The catalysts show high activity in the construction of pyrrolidines, which are accessed with excellent optical purity. Enantiomerically enriched piperidines and indolines are also produced, and various functional groups are tolerated with this LTM system. A reaction mechanism is proposed, and a major
Design, scope and mechanism of highly active and selective chiral NHC–iridium catalysts for the intramolecular hydroamination of a variety of unactivated aminoalkenes
Chiral, cationic NHC–iridium complexes are introduced as catalysts for the intramolecular hydroamination reaction of unactivated aminoalkenes. The catalysts show high activity in the construction of a range of 5- and 6-membered N-heterocycles, which are accessed in excellent optical purity, with various functional groups being tolerated with this system. A major deactivation pathway is presented and
引入手性阳离子 NHC-铱配合物作为未活化氨基烯烃分子内氢胺化反应的催化剂。该催化剂在构建一系列 5 元和 6 元 N 杂环时表现出高活性,这些杂环具有优异的光学纯度,并且该系统可以耐受各种官能团。通过使用替代反应条件呈现和消除主要的失活途径。对反应机理进行了详细的实验和计算研究,为催化系统的作用模式提供了有价值的见解,并指出了对该催化平台的未来修改。