Transamination reactions

Aminoacroleins enter the transamination reaction with 1,2-diaminoethane to furnish bis adduct 217, whereas with 1,2-diaminobenzene they yield the 2 2 macrocyclic adduct 218 (77CZ161). 

The transamination reaction on 3,4-diamino-1,2,5-thiadiazole 5,5-dioxide 200 with pyridylamines afforded the 3-monoheteroarylamino thiadiazole... 

A transamination reaction on 213 afforded 3-aminosubstituted-thiadiazoline 5,5-dioxides 214 by reacting with the appropriate amine (96MI1). 

Amino acids are metabolized by a transamination reaction in which the —NH2 group of the amino acid changes places with the keto group of an a-keto acid. The products are a new amino acid and a new a-keto acid. Show the product from transamination of isoleucine. 

Hydrolysis of this PMP-n-keto acid imine in step 4 then completes the first part of the transamination reaction. The hydrolysis is the mechanistic reverse of... 

Write all the steps in the transamination reaction of PMP with a-ketoglutarate plus a lysine residue in the enzyme to give the PLP-enzyme inline plus glutamate. 

The reaction of naphthols with ammonia and sodium bisulfite is called the Bucherer reaction. Primary amines can be used instead of ammonia, in which case N-substituted naphthylamines are obtained. In addition, primary naphthylamines can be converted to secondary, by a transamination reaction ... 

Fig. 25.8 (a) Normal metabolism, in which phenylalanine is converted by phenylalanine 4-mono-oxygenase to tyrosine, (b) Phenylketonuria, in which there is a transamination reaction between phenylalanine and a-ketoglutaric acid. Phenylalanine 4-mono-oxygenase is absent in about 1 in every 10000 human beings because of a recessive mutant gene. 

Another interesting example is SHMT. This enzyme catalyzes decarboxylation of a-amino-a-methylmalonate with the aid of pyridoxal-5 -phosphate (PLP). This is an unique enzyme in that it promotes various types of reactions of a-amino acids. It promotes aldol/retro-aldol type reactions and transamination reaction in addition to decarboxylation reaction. Although the types of apparent reactions are different, the common point of these reactions is the formation of a complex with PLP. In addition, the initial step of each reaction is the decomposition of the Schiff base formed between the substrate and pyridoxal coenzyme (Fig. 7-3). 

Amine-phosphorus halide reactions involve hydrogen halide (or amine hydrohalide) formation. They can be complicated through acid catalysis or side reactions. Thus, the possible formation of skeletally stabilized products through transamination reactions in which no hydrohalide products are obtained is of interest. 

The compounds described herein were prepared by three methods. The first route involves deprotonation/substitution at the N-H sites of 1, the second consists of a cleavage reaction of an Si-N derivative of 1 with PhBCI2, and the third route is a transamination reaction between a bis(dimethylamino)boryl derivative of 1 and an aliphatic diamine. In the first approach, compound 1 is deprotonated by treatment with one equivalent of n-BuLi. Quenching of the resulting anion with various electrophiles produces the monosubstituted products 2-4 (eq 3). 

The third method that we have used to prepare these diazaboracyclohexane systems is the transamination reaction of 1,3-diaminopropane with the bis(dimethyiamino)boryl compound 8 (eq 8). The solid products 12 and 13, which contain, respectively, two or three of the BN2C3 heterocycles linked by B-N bonds, could not be distilled (or crystallized), but they were thermally stable to at least 200°C. After minor impurities were removed from 12 by vacuum distillation and from 13 by washing with hexane, the structures were confirmed by1H, 13C, and 11B NMR spectroscopy. 

DNA and RNA may be modified with hydrazide-reactive probes by reacting their cytosine residues with bisulfite to form reactive sulfone intermediates. These derivatives can undergo transamination reactions with hydrazide- or amine-containing probes to yield covalent bonds (Draper and Gold, 1980) (Chapter 27, Section 2.1). 

Figure 27.13 Biotin-hydrazide may be incorporated into cytosine bases using a bisulfite-catalyzed transamination reaction.

Love and coworkers have reported a series of dinuclear cobalt complexes derived from a rigid binucleating macrocycle H4L 18 as shown in Fig. 26 (150). The synthesis of the dicobalt complex [Co2(L18)] (36) was achieved by an anaerobic transamination reaction between H4L18 and [Co(thf) N(SiMe3)2 2] in THF. The unsaturated species 36 forms a bis(pyridine) adduct, 36 py2 (py — pyridine), which has a cleft-like structure reminiscent of pacman diporphyrin complexes (151,152). Both cobalt ions are square pyramidal, with Col and Co2 displaced out of the N4-basal planes by 0.17 and 0.18 A, respectively. The apical sites are occupied by pyridine nitrogen atoms that are exo and endo to the cleft. Interestingly the endo pyridine is canted and reflects the... 

A report dealing with the bronchodilator activity and transamination reactions of 4-aminopyrazino[2,3-c][l,2,6]thiadiazine 2,2-dioxides has been published . 

There are many possible diaminobiphenyls, but only for the 4,4 -species [a.k.a. benzidine (31)] are there enthalpy-of-formation data from this century51. Consider now the formal all-solid transamination reaction... 

Figures 6.2a and b illustrate important examples of transamination reactions.

This shows that glutamate is the ammonia donor. Glutamate itself may be formed from other amino acids by transamination reactions, thus allowing... 

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