Intra- and Intermolecular Hydroamination of Alkynes Catalyzed by ortho-Metalated Iridium Complexes

详细信息    查看全文

• 作者：Rung-Yi Lai ; K. Surekha ; Akito Hayashi ; Fumiyuki Ozawa ; Yi-Hong Liu ; Shie-Ming Peng ; Shiuh-Tzung Liu
• 刊名：Organometallics
• 出版年：2007
• 出版时间：February 12, 2007
• 年：2007
• 卷：26
• 期：4
• 页码：1062 - 1068
• 全文大小：125K
• 年卷期：v.26,no.4(February 12, 2007)
• ISSN：1520-6041

文摘

Reaction of o-(diphenylphosphino)(N-benzylidene)aniline (P~N) with [Ir(COD)Cl]₂ affords thesubstitution product [(P~N)Ir(COD)Cl] (1). Treatment of 1 with AgBF₄ yields the cyclometalated iridiumhydride complex [P,N,C-(P~N)Ir(COD)H]BF₄ (2). On the other hand, under atmospheric pressure ofCO, carrying out the substitution of [Ir(COD)Cl]₂ with P~N results in the formation of [P,N,C-(P~N)Ir(CO)HCl] (5). Conversion of 4 into 5 can be achieved by the reaction of 4 with CO in the presence oftetraethylammonium chloride. Both 4 and 5 are characterized by spectroscopic and X-ray structuralanalyses. All iridium complexes are not good catalysts for hydroamination. However, the combinationof 5 with NaB[3,5-C₆H₃(CF₃)₂]₄ (denoted as NaBAr^F₄) provides a potent catalytic system for both intra-and intermolecular hydroamination of alkynes. Intramolecular reaction of o-(2-phenylethynyl)anilinesproduces the corresponding indoles in good yields. Furthermore, intermolecular hydroamination takesplace smoothly to generate the imine intermediates, which could be subsequently reduced by triethylsilaneusing the same catalyst, giving N-silylated amines. However, the N-silylated amines readily hydrolyze toproduce secondary amines.