Addition primary aliphatic, reaction

Whereas the reactions of allenephosphonates 171 (R2 = OEt) with primary aliphatic and aromatic amines 172 and the reactions of the phosphane oxides 171 (R2 = Ph) with aliphatic amines 172 afford the conjugated addition products 173 always in good yields, the addition of anilines to 171 (R2 = Ph) leads to an equilibrium of the products 173 and 174 [231]. However, treatment of both phosphane oxides and phos-phonates of type 171 with hydroxylamines 172 (R3 = OR4) yields only the oximes 174 [232, 233]. The analogous reaction of the allenes 171 with diphenylphosphinoylhy-drazine furnishes hydrazones of type 174 [R3 = NHP(0)Ph2] [234],... 

Isocyanates and amines react together to form ureas. Primary aliphatic amines react very quickly at temperatures down to ambient, whereas secondary aliphatic and primary aromatic amines react less quickly. The reaction rate of secondary aromatic amines is the slowest. The speed of the reaction can further be modified by the addition of substitutes near the amine group. The control of the speed can either be electronic, as illustrated by the effect of the chlorine in the MOCA ring, or by stereo chemical influences where the groups next to the amine group have a very strong hindrance to the curing. This is... 

A palladium-catalyzed three-component reaction with 2-iodobenzoyl chloride or methyl 2-iodobenzoate, allene and primary aliphatic or aromatic amines to prepare fV-substituted 4-methylene-3,4-dihydro-1 (27/)-isoquinolin-1 -ones was disclosed <02TL2601>. A synthesis of 1-substituted 1,2,3,4-tetrahydroisoquinolines via a Cp2TiMe2-catalyzed, intramolecular hydroamination/cyclization of aminoalkynes was also reported <02TL3715>. Additionally, a palladium-catalyzed one-atom ring expansion of methoxyl allenyl compounds 79 to prepare compounds 80 that can serve as precursors to isoquinolones was reported <02OL455,02SL480>. 

When primary aliphatic isocyanates that show the lowest reactivity compared to secondary or aromatic isocyanates are used in combination with hydrophilic (pre-) polymers, crosslinking may be performed in aqueous solution without the use of additional crosslinkers. At neutral pH, hydrolysis of isocyanates to carbaminic acid with subsequent decarboxylation yields amines. These amines react much more rapidly than water with isocyanates, resulting in crosslinking if the functionality per macromolecule is more than two [43], This crosslinking reaction can be quenched by adjustment of the pH value. At pH values above 10, carbamate formation is faster than decarboxylation, whereas at pH values below 3 an almost quantitative protonation of the formed amino groups results in the formation of ammonium. In both cases, chemical crosslinking is prevented. 

In the case of primary aliphatic amines, the reaction products are dramatically affected by the solvent employed. For instance, in the presence of solvents apt to produce a specific solvation of amines (chloroform, and an amine chlorohydrate solution in methylene dichloride), the reaction with hexachloride precursors terminates to yield the trisubstituted product DD D" formed via route A. At the same time, the use of some other solvents (such as benzene, 1,4-dioxane, THF, methylene dichloride, DMF, and alcohols, or the corresponding amine media) led to the formation of the sole tetrasubstituted product (DD"D"). In addition, in the case of sterically unhindered primary amines an alternative isomer (D D D") is not isolated, which indicates reaction route A and a specific control of the tie reaction in the transition state by solvation interactions and intramolecular hydrogen bonds. In the case of the dichloride FeBd2(C12Gm)(BF)2 precursor, with both primary (cyclohexylamine) and secondary (diethylamine and piperazine) aliphatic amines, only a monosubstituted product of the Bd2D type is formed in chloroform, whereas in some other solvents, a diamine clathrochelate of the Bd2D" type is obtained with both sterically hindered and unhindered primary aliphatic amines. 

Treatment of a primary aliphatic amine with nitrous acid or its equivalent produces a diazonium Ion which results in the formation of a variety of products through solvent displacement, elimination and solvolysis with 1,2-shift and concurrent elimination of nitrogen. The stereochemistry of the deamination-substitution reaction of various secondary amines was investigated as early as 1950, when an Swl-type displacement was suggested. Thus, the process can hardly be utilized for the preparation of alcohols except in cases where additional factors controlling the reaction course exist. Deamination-substitution of a-amino acids can be utilized for the preparation of chiral alcohols. 

Cadmium acetate-Zinc acetate. The catalyst, prepared by heating a mixture of 2.5 g. each of cadmium acetate dihydrate and zinc acetate dihydrate to remove the water of hydration, promotes addition of primary aliphatic amines to acetylene to give ethylidenimines. Thus ethylamine, heated with acetylene and catalyst in an autoclave at 120-140° for 29 hrs., afforded N-ethylethylidenimine (1). Catalyzed reaction... 

Note that primary aliphatic amines having a hydrogen on the alpha-carbon can display additional metabolic reactions, shown as reaction 5 in Fig. 13.5. Indeed, N-oxidation may also yield imines (reaction 5-A), whose degree of oxidation is equivalent to that of hydroxylamines (45). Imines can be further oxidized... 

Dissolving 3-aryl(alkyl)-1,2,4,5-tetrazines (21) in liquid ammonia or primary aliphatic amines at — 35°C to — 40°C, followed by addition of potassium permanganate, gives 6-alkylamino-3-aryl-(alkyl)-1,2,4,5-tetrazines (23) in reasonable to excellent yields. This shows that, under the reaction conditions, addition of A-nucleophiles to the tetrazine ring must have occurred (Scheme 1) <8 JHC123>. The presumption of a 1,6-dihydro intermediate (22) rests on the experimental result that tetrazines can be transformed by sodium borohydride into the isolable 1,6-dihydro-1,2,4,5-tetrazines, which can be considered as neutral homoaromatic systems <8UOC2i38>. 

Aliphatic aldehydes are also obtained with high selectivity. Selectivity is lower for primary aliphatic carboxylic acids because of a competing intermolecular decarboxylation reaction which results in ketone formation (Eq. 2) [16]. This ketonization activity of Zr02 was, substantially suppressed by addition of metal ions. 

The reaction is of broad scope being applicable to primary aliphatic bromides, benzylic bromides and aryl bromides although in the latter cases, an additional palladium catalyst [PdfPPh J ] is required. With reaction temperatures of 150°C and CO pressures of 80-100 p.s.i., yields are generally in excess of 80%. The success of this method with primary aliphatic bromides is also noteworthy as such systems often undergo 8-eliminations rather than carbonylation a new platinum catalyst has been developed which also does not suffer appreciably from this limitation.1 5... 

In addition to accelerating degradation rates for halogenated aliphatics, reaction with sulfur nucleophiles will have significant consequences with respect to reaction product distributions. Schwarzenbach et al. (1985) have observed the formation of thiols and dialkyl sulfides from the Sn2 reactions of primary alkyl bromides with HS (Figure 2.12). 

Addition copolymers containing IBM retain much of this reactivity with primary alcohols. As seen in Table 3, the reaction rate constant of 1-butanol with polymerized IBM is about half that of monomeric IBM under the same conditions (3). Thus the reactivity of IBM-containing polymers is similar to that of other primary aliphatic isocyanates such as hexamethylene diisocyanate. This very good retention of NCO reactivity allows the use of IBM to incorporate NCO functionality into a variety of vinyl copolymers. In general, IBM-containing copolymers retain >90% of the theoretical isocyanate functionality. 

Vajda and Kovacs described three methods labeled A, B, and C, for the direct amination of the pyridine with alkyl amines in the presence of sodium amide or finely divided potassium or sodium metal. An example of method A was the preparation of 2-M-butylaminopyridine from a mixture of n-butylamine, pyridine, and sodium amide in boiling toluene (60 hours). In method B, powdered sodium (or potassium) metal was used instead of sodium amide and the reflux time was 20 hours. Method C employed sodium metal, a bath temperature of 120°, boiling under reflux with stirring for 3 hours and an additional 7 hours of boiling without stirring. The yields of 2-n-butylamino-pyridine in the above three methods were 38%, 50%, and 33%, respectively. These authors claimed that the reaction proceeded via a radical rather than an ionic (nucleophilic) pathway because dipyridyls were also formed. When a pyridine is heated with a three- to fourfold excess of a primary aliphatic amine in the presence of finely divided sodium metal, 70 to 80% yields of 2-alkylaminopyridines are obtained. ... 

The application of this procedure to the condensation of a-nitroalkanones with a-alkyl-q ,j8-imsaturated aldehydes afforded, in a one-pot synthesis, functionalized, bridged, and bicyclic lactones containing 10-, 11-, 13-, and 15-membered rings. Recently, Ballini et al. showed that the Michael addition of primary aliphatic nitro compounds to a,p -unsaturated enones performed in aqueous media provided the one-pot synthesis of 1,4-diketones, 1,4-diols, S-nitroalkanols, or hydroxytetrahydrofurans by appropriate choice of reaction conditions. ... 

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