Mechanisms of amines

Tuazon, E. C., W. P. L. Carter, R. V. Brown, R. Atkinson, A. M. Winer, and J. N. Pitts, Jr., "Atmospheric Reaction Mechanisms of Amine Fuels, Report No. ESL-TR-82-17, U.S. Air Force Engineering and Services Center, Tyndall Air Force Base, FL, March 1982. 

Only Sn(AE) and Sn(ANRORC) mechanisms require the formation of anionic ff-adducts. A great deal of attention has been paid to the correlation of the formation of these adducts with the mechanism of amination. However, inasmuch as a detailed account of the latter reaction is outside the scope of this chapter, we report only a few typical sequences proposed in the literature and suggest that the reader gain more information on this point from the outstanding work by van der Plas and his group. 

The adsorption of ammonia and amines has been studied many times as a method of estimation of the acidity of solid surfaces. Some of the results are pertinent to the mechanism of amine transformation on these catalysts. Depending on the structure of the catalyst surface, several types of adsorbed species have been observed. 

The reaction mechanism of amine deamination and disproportionation has been put forward by analogy with other eliminations, namely dehydration and dehydrochlorination [149,155], its characteristic feature being the cooperation of acidic and basic sites. In the deamination, /3-hydrogen and the NR2 group (R is hydrogen or alkyl) are eliminated by an E2-like mechanism on alumina, but by an El-like mechanism on silica-alumina. The nature of the acidic sites is not clear, protons from surface hydroxyls or aluminium ions are possible candidates. However, it seems... 

Another anomaly which calls for revision of the "simple mechanism of amine-initiated polymerisation of NCA was first reported by Blout... 

The known properties of proteins and the known mechanism of amine-catalyzed decarboxylation of /3-oxo acids (Laursen, 1966) were combined to generate a synthetic decarboxylase in the form of two tetradecameric peptides, termed Oxaldie 1 and 2, with leucine and lysine as the main amino acids (Johnsson, 1993). 

The widely accepted mechanism of amine catalysis of the Baylis-Hillman reaction... 

Mechanism of Amination Catalyzed by Palladium Complexes with Sterically Hindered Alkyl Monophosphines... 

Secondary amines are easily oxidized to hydroxylamines. Side products are often formed, however, and the yields may be low. The mechanisms of amine oxidations are not well characterized, partly because many reaction paths (especially those involving free radicals) are available. 

Mechanism of Amine-Catalyzed Intermolecular Aldol Reactions... 

The mechanism by which amines are oxidised by flavoproteins has been an issue of considerable debate in recent years. The debate has been particularly heated in the case of the enzyme monoamine oxidase (Silver-man, 1995). Through the use of a variety of mechanism-based inhibitors and based on studies of nonenzymic mechanisms of amine oxidation, a mechanism for monoamine oxidase in which substrate is initially oxidized by single electron transfer to the enzyme flavin to give an aminium cation... 

The catalytic mechanism of amine oxidases can be fonnally divided into reductive and oxidative half cycles... 

The mechanism of amine intercalation has been investigated by measuring the change in pH as amine is added to a suspension of a-ZrP. Several intermediate compositions are observed en route to the fully exchanged phase. When n-propylamine is used in this reaction, at a point when about one half of the protons have been titrated, the a-ZrP layers spontaneously exfoliate. Presumably the hydrogen bonding interlayer interactions are reduced and not compensated by interchain van der Waals forces. Addition of more propylamine causes the layers to reflocculate. 

Scheme 8 Mechanism of amine oxidase. (Ref 73. Reprodnced by permission of Springer Verlag)...

Edmondson DE, Binda C, Mattevi A. Structural insights into the mechanism of amine oxidation by monoamine oxidases A and B. Arch. Biochem. Biophys. 2007 464 269-276. 

Kwart, H., Brechbiel, M. Role of solvent in the mechanism of amine oxide thermolysis elucidated by the temperature dependence of a kinetic isotope effect. J. Am. Chem. Soc. 1981, 103,4650-4652. 

Resonance line broadening due to chemical exchange and quadrupole-induced relaxation in the H and nB n.m.r. spectra of some boron-nitrogen adducts ArNMe2,BY3 (Y = halogen) has been observed and used to determine the mechanism of amine scrambling in these adducts.165 This is thought to occur via a unimolecular ionization rather than a B—N bond-rupture process. 

Scheme 6.3.11 The mechanism of amination of tri-n-butylphenoxytin with DEAD via a Wheland intermediate...

Scheme 6.3.12 The mechanism of amination of 2-(tri-n-butyistannyloxy)naphthalene with DEAD. The met-aiioene mechanism...

SB Karki, JP Dinnocenzo. On the mechanism of amine oxidations by P450. Xenobiotica 25 711-724, 1995. 

Scheme 6,22 Mechanisms of amine iV-phenylation as suggested by Barton et...

Figure 8. Reaction acceleration mechanism of amine (nucleophilic reaction of amine).

Reactions of Aminyl Radicals and Mechanisms of Amine Regeneration as Inhibitors of Oxidation... 

Although H-transfer in flavoprotein amine dehydrogenases has been shown to occur by tunneling, the mechanisms of amine oxidation by flavoproteins remain controversial. Over the years mechanisms involving the following have been con-... 

The postulated catalytic mechanism of amine oxidases starts from the qui-none form of the cofactor (Fig. 17). The distal oxygen atom is replaced by an amino group in a transamination reaction. The amine is then re-oxidized by molecular oxygen to the original quinone. The copper ion is not involved directly in catalysis but is only a cofactor in the synthesis of TOPA quinone (Fig. 18). 

Scheme 5 Alternative mechanisms of amine oxidation by monoamine oxidase.

A different approach has been reported by Benner and his group, [26] who based the design of a synthetic decarboxylase on the known properties of proteins and the mechanism of amine-catalysed decarboxylation of 0-ketoacids. Their enzyme mimics are 14-... 

Use your knowledge of the mechanisms of amine reactions to propose mechanisms and products of similar reactions you have never seen before. 

Structure and Mechanism of Amine Oxidase Histone Demethylases... 

Farkas A, Strohm PF (1965) Mechanism of Amine-Catalyzed Reaction of Isocyanates with Hydroxyl Compounds. Ind. Eng. Chem. Fundam. 4 32-38. 

Figure 50 (a) Retroaldol reaction of sodium 4-phenyl-4-hydroxy-2-oxobutyrate 135 and the mechanism of amine catalysis,... 

In his classic paper on the mechanism of amination of halobenzenes Roberts expended considerable effort and ingenuity to eliminate alternatives to the aryne mechanism. In particular he convincingly demonstrated that no rearrangement of the starting aryl halide took place. Such rearrangements do occur under aryne forming conditions, however, with polyhalobenzenes and a variety of monohaloheterocycles. This reaction has been labeled the... 

There have been no detailed investigations of the mechanism of amine halogenation by hypohalite. In chlorination the reactive species... 

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