3096-95-5Relevant articles and documents
Unprecedented Copper(II) Complex with a Topoquinone-like Moiety as a Structural and Functional Mimic for Copper Amine Oxidase: Role of Copper(II) in the Genesis and Amine Oxidase Activity
Jangir, Ritambhara,Ansari, Mursaleem,Kaleeswaran, Dhananjayan,Rajaraman, Gopalan,Palaniandavar, Mallayan,Murugavel, Ramaswamy
, p. 10940 - 10950 (2019/11/13)
Copper amine oxidase (CAO), consisting of the topoquinone (TPQ) cofactor, catalyzes the oxidation of primary amines to aldehyde. We have successfully addressed this issue through isolation of a copper complex which mimics the active-site structure as well as the function of CAO. This inimitable complex, consisting of two TPQ-like side-arms, formed by ambient aerial oxidation of a precursor Schiff base complex, is the most efficient homogeneous catalyst for quantitative oxidation of primary benzylic amines to corresponding secondary imines under ambient conditions within 30 min. The longstanding contention of actual involvement of Cu(II) in the catalysis is resolved through quenching experiments of Cu(II) superoxo species and detailed density functional theory studies.
Synthesis of Imines via Reactions of Benzyl Alcohol with Amines Using Half-Sandwich (η6-p-cymene) Ruthenium(II) Complexes Stabilised by 2-aminofluorene Derivatives
Vinoth, Govindasamy,Indira, Sekar,Bharathi, Madheswaran,Durgadevi, Anandhan,Abinaya, Ravikumar,Alves, Luis G.,Martins, Ana Margarida,Bharathi, Kuppannan Shanmuga
, (2019/09/03)
A new class of half-sandwich (η6-p-cymene) ruthenium(II) complexes supported by 2-aminofluorene derivatives [Ru(η6-p-cymene)(Cl)(L)] (L?=?2-(((9H-fluoren-2-yl)imino)methyl)phenol (L1), 2-(((9H-fluoren-2-yl)imino)methyl)-3-methoxyphenol (L2), 1-(((9H-fluoren-2-yl)imino)methyl)naphthalene-2-ol (L3) and N-((1H-pyrrol-2-yl)methylene)-9H-fluorene-2-amine (L4)) were synthesized. All compounds were fully characterized by analytical and spectroscopic techniques (IR, UV–Vis, NMR) and also by mass spectrometry. The solid state molecular structures of the complexes [Ru(η6-p-cymene)(Cl)(L2)], [Ru(η6-p-cymene)(Cl)(L3)] and [Ru(η6-p-cymene)(Cl)(L4)] revealed that the 2-aminofluorene and p-cymene moieties coordinate to ruthenium(II) in a three-legged piano-stool geometry. The synthesized complexes were used as catalysts for the dehydrogenative coupling of benzyl alcohol with a range of amines (aliphatic, aromatic and heterocyclic). The reactions were carried out under thermal heating, ultrasound and microwave assistance, using solvent or solvent free conditions, and the catalytic performance was optimized regarding the solvent, the type of base, the catalyst loading and the temperature. Moderately high to very high isolated yields were obtained using [Ru(η6-p-cymene)(Cl)(L4)] at 1?mol%. In general, microwave irradiation produced better yields than the other two techniques irrespective of the nature of the substituents.
An investigation of the effects of CeO2 crystal planes on the aerobic oxidative synthesis of imines from alcohols and amines
Zhang, Zhixin,Wang, Yehong,Wang, Min,Lü, Jianmin,Li, Lihua,Zhang, Zhe,Li, Mingrun,Jiang, Jingyang,Wang, Feng
, p. 1623 - 1630 (2015/09/15)
We herein report the effects of CeO2 crystal planes on the oxidative coupling of alcohols and amines to form imines. CeO2 exhibits significant catalytic activity under mild reaction conditions (60 °C) during the synthesis of 13 different imines, giving >89% conversions and >90% selectivities. The crystal planes of CeO2 greatly affect the catalytic performance. Among the crystal planes investigated (the (110), (100) and (111) planes), the (110) plane shows the strongest redox ability and thus the best catalytic activity, generating a 97% yield of the imine at 60 °C in 2 h, because it contains the highest concentration of oxygen vacancies.
