Pyridine amination

The heavier chalcogens are more prone towards secondary interactions than sulfur. In particular, the chemistry of tellurium has numerous examples of intramolecular coordination in derivatives such as diazenes, Schiff bases, pyridines, amines, and carbonylic compounds. The oxidation state of the chalcogen is also influential sulfur(IV) centres engender stronger interactions than sulfur(II). For example, the thiazocine derivative 15.9 displays a S N distance that is markedly longer than that in the corresponding sulfoxide 15.10 (2.97 A V5. 2.75-2.83 A, respectively). ... 

Hexadentate ligands l,12-bis(2-pyridyl)-5,8-dioxa-2,ll-diazadodecane and l,12-bis(2-pyridyl)-5,8-dithia-2,ll-diazadodecane have pyridine, amine, and ether or thioether donors offering an N402 or N4S2 donor set. The X-ray structures of the zinc complexes are distorted octahedral with the zinc center encapsulated by the ligand.898... 

As has already been mentioned, boron halides are electron-deficient molecules. As a result, they tend to act as strong Lewis acids by accepting electron pairs from many types of Lewis bases to form stable acid-base adducts. Electron donors such as ammonia, pyridine, amines, ethers, and many other types of compounds form stable adducts. In behaving as strong Lewis acids, the boron halides act as acid catalysts for several important types of organic reactions (see Chapter 9). 

Marcinek and Platz used the pyridine-ylide method to measure absolute rate constants of reactions of two para-substituted perfluorophenylnitrenes (16h, 16j) with pyridine, amines, isoprene. 2,3-dimethyl-2-butene and other quenchers (Table 11). 

Not listed and therefore not permitted are substances from chemical groups like pyrazines, pyridines, amines, amides, or aliphatic lower alcohols, aldehydes and hydrocarbons (C5 and lower) if not mentioned by individual name [17]. 

The shifts in the statistically weighted average e/b2 IE values compared to the IE value for the t2g MOs of Cr(CO)6 (8.40 eV) are in the order pyridine > amine > sulfide > phosphine. This order is similar to that observed for the shifts... 

These coordinatively unsaturated complexes can undergo coordination reactions with compounds having a free electron-pair donor group, particularly pyridine, amines, ammonia, and water. Coordination is associated with a marked hyp-sochromic color change. For example, the unsaturated nickel complex36 is green and its pyridine adduct 37 is violet [74],... 

Complexation via the ligand method of more than 70 % of the Cu and Fe ions in zeolite Y with a mixed tridentate NJ f,O-ligand such as (2-hydroxymethyl) (2-methyl-pyridine)amine (Hbpa) was reported, yielding entrapped Fe(bpa) (8) together with residual uncomplexed rhombohedral Fem with an ESR signal at g = 4.3 and Fe-Fe interactions with g = 2.0/1121 When a more than stoichiometric amount of Hbpa... 

Pyridines, Amines, and Phosphines. We have not observed an ESR signal during the autoreduction with the above substrates. With the pyridines and phosphines so far investigated, the reduction probably has been too slow to generate appreciable concentrations of radical species. The autoreduction is much faster with primary and secondary amines, however the radicals produced are most likely too short-lived to detect with our present methods. We are investigating the applicability of rapid flow and spin trapping techniques. 

As a result of their being able to react as Lewis acids, compounds having the formula SnX2 also form many complexes with molecules containing O and N as the electron donor atoms (H20, pyridine, amines, aniline, etc.). 

Several unique heterocyclic fused-1,2,4-triazole structures have been published. Pyridine amination of 216 with O-mesitylenesulfonylhydroxylamine followed by condensation with various aryl and heterocyclic aldehydes and subsequent cyclization and oxidation gave triazolopyridines 217 <03TL1675>. Triazolopyridines 217 were utilized in the direct conversion to the triazolopyridine amides 218 with methylaluminoxane premixed with amines in a combinatorial library synthesis. A convenient synthesis of novel 4-(l,2,4-triazol-l-yl)-2-pyrazolines and their derivatives has been reported <03SC1449>. A novel triheterocyclic ring system, thieno[2,3-y][l,2,4]triazolo[l,5-a]azepines, has been published <03S1231>. 

M—O—O—M, M = Co % Cu, p-peroxodimethyl complexes with pyridine, amine ligands Comba 1997b... 

In flat flame laboratory experiments, Shaw and Thomas (28) have shown that addition of fuel nitrogen compounds such as pyridines, amines, and cyanides to CO flames increases the NOa emissions. Values to 1300 ppm NOa were measured with and without molecular nitrogen during low temperature CO combustion (860-1145°K). Both CO-02-argon and CO-O2-N2 mixtures were studied with maximum conversions of about 40-50% of the fuel nitrogen to NOar. 

The process is suppressed by typical inhibitors of cationic (substances containing atoms with an unshared electron pair pyridine, amines, DMF, ketones, alcohols, nitriles) or anionic (ethyl chloride and acetonitrile) polymerization. Water, methanol, and ammonia are universal ionic inhibitors which affect radical processes only slightly. 

Directions for the preparation of 2-(benzylamino)pyridine in 99% yield from 2-pyridin-amine and benzyl alcohol are given in Organic Syntheses.1047... 

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