1 - methanamine, reaction

Compound 139 was synthesized by the reaction between macrocyclic triamine 138 and dimethoxy-Ar,Ar-di m e t hy 1 -methanamine in ethanol under reflux conditions (Equation 17) <1996JOC2020, 1997TL1911, 2001TL2735, 2004BCC174>. 

The unshared electrons on nitrogen play a key role in the reactions of amines. In fact, almost all reactions of amines at the nitrogen atom have, as a first step, the formation of a bond involving the unshared electron pair on nitrogen. A typical example is acylation, which is amide formation through the reaction of an acyl chloride, an anhydride, or an ester with an amine. The initial step in these reactions with benzenecarbonyl derivatives and methanamine as illustrative reactants is as follows ... 

Despite the fact that alkylation reactions of amines generally give mixtures of products, they are of practical value on an industrial scale. The commercial synthesis of methanamines uses methanol as the methylating agent and alumi-... 

Some care must be exercised in the reduction of nitro compounds because such reductions can be highly exothermic. For example, the reaction of 1 mole (61 g) of nitromethane with hydrogen to give methanamine liberates sufficient heat to increase the temperature of a 25-lb iron bomb 100° ... 

Exercise 25-8 The reactions that lead to the blue color produced between ninhydrin and a-amino acids are examples of reactions discussed previously in the context of carbonyl chemistry (see, for instance, Section 16-4C). Write mechanisms, based insofar as possible on analogy, for each of the steps involved in the ninhydrin test, using glycine as an example. Would you expect ammonia or methanamine to give the blue color Explain. 

Chromans possessing a fused isoxazolidine moiety 505 can be accessed via a palladium-catalyzed allene insertion-intramolecular 1,3-dipolar cycloaddition cascade reaction between ( )-fV-(2-hydroxybenzylidene)methanamine oxide, allene, and aryl iodides. This process creates two rings, two stereocentres and a quaternary carbon centre in one-pot (Equation 210) <2002CC1754>. 

The 3-indolyl methanamine structural motif 503 is embedded in numerous indole alkaloids and synthetic indole derivatives . An efficient catalytic asymmetric Friedel-Crafts reaction of indoles 501 with imines 502 provides a direct, convergent, and versatile method for the highly enantioselective construction of 3-indolyl methanamines 503 from readily accessible achiral precursors (Scheme 101) <2006JA8156 and references therein>. 

The first intermolecular C-N bond-forming reactions between substituted 2-bromopyrroles 1450 and 1453 with primary (Tpropanamine, 2-methoxy-l-ethanamine, (4-methoxyphenyl)methanamine, cyclopropanamine, cyclobuta-namine), and cyclic secondary amines (pyrrolidine, morpholine, 1-methylpiperazine, ethyl tetrahydro-l(27/)-pyrazi-necarboxylate, 1-phenylpiperazine, l-(3-phenyl-2-propenyl)piperazine) 1451 were performed using Pd2(dba)3 as catalyst with BINAP as the ligand. The aminations proceeded in the presence of Bu ONa at 80-100 °C in 31-93% yields (Equations 301 and 302) <2004TL769>. However, when the above optimized conditions were applied to the coupling reaction of pyrrole 1450 and acyclic secondary amines such as di- -butylamine, diphenylamine and dipropenylamine, no reaction was observed. 

To examine the syn/anti selectivity, Houk examined the aldol reaction of acetaldehyde and propanal with methanamine as catalyst. Reaction 6.19. The E or Z enamine can react to give syn or anti product. They located four TSs 52a-d, shown in Figure 6.22. Again, these TSs are in a half-chair conformation with internal proton transfer. The TSs involving the E isomer are lower than those with the Z isomer. The E isomer prefers to give the anti isomer (52a is 0.7 kcal mol" below 52b), while the Z isomer favors the syn product (52c is 1.4 kcal mol" below 52d) These results are consistent with experiments that show preference... 

The Friedel Crafts (F C) reaction via activation of electrophiles functionalized by a nitrogen atom, such as imines, is undoubtedly the most practical and atom eco nomical approach to introduce a nitrogen substituted side chain to aromatic com pounds. The enantioselective version of the F C reaction of nitrogen substituted substrates, including imines, with electron rich aromatic compounds enables effi cient access to enantioenriched aryl methanamine derivatives [37[. Several excellent approaches to highly enantioselective F C reactions have been established using chiral phosphoric acid catalysts. 

The reaction between butanoyl chloride and methanamine to produce N-methylbutanamide is an example of an acyl group transfer reaction. 

Phenylacetaldehyde was readily converted into allylic alcohol 81 by a standard olefination and reduction protocol. Epoxidation with t-BuOOH and catalytic Ti(OPr-i)4 in the presence of catalytic (-)-DIPT gave (2R, 3R)-3-benzylglycidol 82 in >99% e.e. Addition of diphenyl-methanamine and Ti(OPr-i)4 in refluxing 1,2-dichloroethane led to aminodiol 83, from which aminoepoxide (S,S)-84 was obtained by hydrogenolysis and /V-protection followed by an intramolecular Mitsunobu reaction [76]. 

Caution. All reactions involving noxious reagents (methanamine, ethanamine, etc.) or corrosive substances such as gaseous hydrogen chloride and must be carried out in a well-ventilated fume hood. 

The AFC reaction of indoles with less reaetive aryl aldimines catalyzed by organocatalystwas reported by the group of Deng in 2006. Bifunctional cinchona alkaloid-derived thioureas were utilized to promote the AFC reaetion of indoles with N-Ts- or AT-Bs-protected imines. With 10 mol% of eatalyst 29, 3-indolyl methanamine derivatives 30 were obtained in high yields with up to 97% ee for both aryl and alkyl imines (Scheme 6.12). 

There are three structural types of amines, as discussed in Chapters 5 and 27 primary amines (RNHg), secondary amines (R2NH), and tertiary amines (RgN). Base strength differs for these amines and also for two different secondary amines or two different tertiary amines. A comparison of ammonia (NHg) with methanamine (27 methyamine) shows that 27 is more basic. In the reaction of 27 with water, the conjugate acid is ammonium salt (28) and the conjugate base is the hydroxide. The for this reaction is small, as indicated by the equilibrium arrows this means that the equilibrium lies to the left. A consequence of this observation is that the hydroxide ion is more basic than amine... 

Small fire attack on a limited area of a product Level of exposure E burning cigarette Acceptable reaction to fire Limited spread of flame and smoke production Documents Methanamine pill test Extent ofdamaged area... 

Scheme 10.19. A representation of a pathway to diazomethane (CH2N2) by nitrosation of methylamine (methanamine, CH3NH2) with nitrous acid (HONO). Generally, any diazomethane (CH2N2) formed under these conditions decomposes before it can be used in subsequent reactions.

A convenient and clean water-mediated synthesis of a series of indolo[l,2-c] quinazoline derivatives was reported using alternative nonconventional energy sources. The products are obtained in shorter times with excellent yields (78-89 %) from the MCR of 2-arrrinobenzimidazole, malononitrile, and carbonyl compourtds [55]. In their research, 2-(2-halophenyl)-lH-indoles arrd (aryl)methanamines were adopted as raw rrraterials to generate corresponding Schiff base via the Ullrrrarm reaction. Thert, gas as oxidarrt, 3 equiv K COj as base, and 10 mol% Cu(OAc)2 as catalyst were revealed as the optimum conditions to conduct aerobic oxidative C-H amination under solvent-free conditions or water (Scheme 13.14). 

PROBLEM 16.73 The Imine formation reaction shows the methanamine attacking acetone in the first step. The alkoxide intermediate is then protonated by an acidic ammonium species in a proton transfer process. It is known that imine formation occurs faster under slightly acidic conditions (pH 5). Why not show the acetone being protonated in the first step as we did in Carbonyl hydration and Acetal formation Select the LUMO track for this animation and examine this MO on acetone by pausing the reaction at the beginning. There are several important facts that are confirmed by this calculated image. Which atom of the molecule has the most LUMO density ... 

Readily available chiral amines related to the Betti base [phenyl(2-hydroxy-l-naphthyl)methanamine] catalyse enantioselective addition of diethylzinc to aldehydes in moderate to excellent ee Observed enantioselectivities in addition of diethylzinc to aldehydes catalysed by a series of (5)-proline-derived pyrrolidines have been explained in terms of steric effects. New 2,5-diazabicyclo[2.2.1]heptanes have been applied to enantioselective addition of diethylzinc to benzaldehyde. (S)-2-(3-Methyl-2-pyridyl)-3,5-di-r-butylphenol (76) has been used as an enantioselective catalyst of diethylzinc addition to benzaldehydes. Reaction in toluene shows a significant variation in % ee with temperature, including observation of an inversion temperature with maximum ee. This value varies with the nature of the para-substituent in the aldehyde, and the overall behaviour may be due to a shift in the rate-determining step of the reaction. Other reports of zinc reagents include enantioselective addition of diethylzinc to aldehydes addition of diphenylzinc to aldehydes using a chiral ferrocene-based hydroxyoxazoline catalyst in up to 96% ee and 3-exo-morpholinoisoborneol has been proposed as a more convenient and efficient enantioselective catalyst of alkylzincs than Noyori s original 3-exo-dimethylamino catalyst. ... 

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