Oxidation of Primary Amines to Oximes with Molecular Oxygen using 1,1-Diphenyl-2-picrylhydrazyl and WO3/Al2O3 as Catalysts

2013 ◽  
Vol 78 (6) ◽  
pp. 2301-2310 ◽  
Author(s):  
Ken Suzuki ◽  
Tomonari Watanabe ◽  
Shun-Ichi Murahashi
Keyword(s):  
Molecular Oxygen ◽  
Primary Amines

scholarly journals Broadening the chemical scope of laccases: selective deprotection of N-benzyl groups

2015 ◽  
Vol 17 (5) ◽  
pp. 2794-2798 ◽  
Author(s):  
Lía Martínez-Montero ◽  
Alba Díaz-Rodríguez ◽  
Vicente Gotor ◽  
Vicente Gotor-Fernández ◽  
Iván Lavandera
Keyword(s):  
Molecular Oxygen ◽  
Trametes Versicolor ◽  
Aqueous Media ◽  
Amino Alcohols ◽  
Primary Amines ◽  
Amino Esters

The chemoselective deprotection of N-benzylated primary amines, amino esters, diamines and amino alcohols in aqueous media using molecular oxygen as a mild oxidant has been demonstrated combining laccase from Trametes versicolor and TEMPO.

Oxygen activation in a copper-containing amine oxidase

2003 ◽  
Vol 31 (3) ◽  
pp. 493-496 ◽  
Author(s):  
C.M. Wilmot
Keyword(s):  
Molecular Oxygen ◽  
Amine Oxidase ◽  
Oxygen Activation ◽  
Structural Basis ◽  
Primary Amines ◽  
Catalytic Intermediates ◽  
H2o2 Formation ◽  
Additional Release ◽  
Colour Changes ◽  
Trihydroxyphenylalanine Quinone

The process by which molecular oxygen is activated to enable it to function as an electron acceptor in biology is poorly understood. The quinoprotein copper-containing amine oxidase (CuAO) catalyses the conversion of primary amines into aldehydes. As well as copper, the enzyme contains an organic cofactor, 2,4,5-trihydroxyphenylalanine quinone (TPQ). Following the formation of aldehyde, the enzyme is left as the two-electron reduced aminoquinol form. Reoxidation of the enzyme back to the resting state uses molecular oxygen, which is reduced to H2O2 in the process, with the additional release of NH3. To understand the structural basis of oxygen activation in Escherichia coli CuAO (ECAO), catalytically competent crystals were used to trap catalytic intermediates by exposing then to amine substrate and then freeze-trapping under aerobic and anaerobic conditions. Single-crystal visible microspectrophotometry was used to probe the oxidation state of the quinone in the intermediates, as TPQ exhibits a rich palette of colour changes during catalytic turnover. This review will focus on one of these structures, that of the rate-determining species in the crystal under steady-state conditions. This structure has revealed many details regarding oxygen activation in ECAO, including the site of dioxygen binding, and the proton-transfer pathways involved in H2O2 formation.

scholarly journals One-pot, three-component condensation of 2-hydroxybenzaldehyde derivatives, primary amines with alkyl isocyanides to N-alkyl-2-(2-hydroxyphenyl)-2-imino-acetamides

2010 ◽  
Vol 8 (4) ◽  
pp. 899-905 ◽  
Author(s):  
Mehdi Ghandi ◽  
Parham Asgari ◽  
Abuzar Taheri ◽  
Alireza Abbasi
Keyword(s):  
Molecular Oxygen ◽  
Primary Amines ◽  
One Pot ◽  
Subsequent Oxidation ◽  
Alkyl Isocyanides ◽  
Oxidation With Molecular Oxygen

AbstractOne-pot, three-component condensation of 2-hydroxybenzaldehyde derivatives, primary amines with alkyl isocyanides is reported. N-alkyl-2-(2-hydroxyphenyl)-2-iminoacetamide derivatives are generated presumably via the preliminary formation of N, N′-disubstituted benzo[b]furan-2,3-diamines and subsequent oxidation with molecular oxygen.

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