Nitrogen Bond Formation

The vapor phase N-alkylation of aniline with ethanol took place over an H-ZSM-5 catalyst at temperatures between 250° and 500°C. The maximum selectivity for N-monoethylation occurred at the lower temperatures with increasing amounts of diethyl aniline produced at higher reaction temperatures. v/ith montmorillonite catalyst, reaction at 400°C gave a 64% selectivity for N-ethyl aniline formation at 77% conversion. A vanadium exchanged montmorillonite was more active but less selective giving N-ethyl aniline in 48% selectivity and N, N-diethyl aniline in 37% selectivity at 97% conversion.94 

The vapor phase reaction of butane diol with methyl amine at 300°C in the presence of a Cr-ZSM-5 catalyst gave a 65% yield of N-methyl pyrrolidine, 42 (Eqn. 22.41). Tetrahydrofuran was also converted to 42 in 98% yield under these conditions. 5 

Reaction of sulfur dioxide with the imine, 43, over a ZSM-5 catalyst gave 4-methylthiazine (44) in yields as high as 65% (Eqn. 22.42).  

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Azide ion ( N=N=N ) Sodium azide IS a reagent used for carbon-nitrogen bond formation The product IS an alkyl azide... 

Methods for Carbon-Nitrogen Bond Formation Discussed in Earlier Chapters... 

The preparation of amines by the methods described m this section involves the prior synthesis and isolation of some reducible material that has a carbon-nitrogen bond an azide a nitrile a nitro substituted arene or an amide The following section describes a method that combines the two steps of carbon-nitrogen bond formation and reduction into a single operation Like the reduction of amides it offers the possibility of prepar mg primary secondary or tertiary amines by proper choice of starting materials... 

In the modified Raschlg process , used by Bayer A.G. and by Mobay Chem. Co. for large scale production of hydrazine, the intermediacy of an oxaziridine could be clearly evidenced (81MI50800). In this process ammonia and hypochlorite are reacted in the presence of acetone to form ketazine (302). Nitrogen-nitrogen bond formation is faster by a factor of about 1000 in the presence of acetone than in its absence. Thus acetone does not merely trap hydrazine after formation, but participates in the N —N bond forming reaction. Very fast formation of oxaziridine (301), which is isolable, is followed by its likewise fast reaction with ammonia. 

B. Carbon—Carbon and Carbon—Nitrogen Bond Formation. 208... 

Jiang L, Buchwald SL (2004) Palladium-catalyzed aromatic carbon-nitrogen bond formation. In de Meijere A, Diedeiich F (eds) Metal-catalyzed cross-coupling reactions, 2nd edn. Wiley-VCH, Weinheim... 

Transition metal complex-catalyzed carbon-nitrogen bond formations have been developed as fundamentally important reactions. This chapter highlights the allylic amination and its asymmetric version as well as all other possible aminations such as crosscoupling reactions, oxidative addition-/3-elimination, and hydroamination, except for nitrene reactions. This chapter has been organized according to the different types of reactions and references to literature from 1993 to 2004 have been used. 

An important variant for transition metal-catalyzed carbon-nitrogen bond formation is allylic substitution (for reviews, see1,la lh). Nucleophilic attack by an amine on an 7r-allyl intermediate, generated from either an allylic alcohol derivative,2 16,16a 16f an alkenyloxirane,17-19,19a-19d an alkenylaziridine19,19a 19d, or a propargyl alcohol derivative,21,21a 21d gives an allylic amine derivative. 

More generally, electrolytically formed electrophilic centers react with nucleophilic centers. For example, in Scheme 4 [7], an electrogenerated nitroso group leads to a nitrogen-nitrogen bond formation after reaction with an amino group. When the electrolysis is performed in a batch cell, a rapid cyclization... 

Carbon-Nitrogen Bond Formation A carbon-nitrogen bond can result either from the reaction between an anodically produced cationic center and an amino group or from the reaction between a nucleophilic center and an electrogenerated electrophilic nitrogen... 

Nitrogen-Nitrogen Bond Formation Triazole derivatives may be obtained by the electrooxidation of molecules containing several nitrogen atoms as illustrated in Scheme 39 [57]. 

Carbon-Nitrogen Bond Formation The cathodic reduction, in protic media, of aromatic nitro compounds produces nucleophilic centers, either... 

Nitrogen-Nitrogen Bond Formation The cathodic reduction of o-nitroazobenzenes in a basic medium leads to benzotriazole N-oxides (Scheme 82) [119-121]. 

Carbon-Nitrogen Bond Formation Based on Hydrogen Transfer 123 Table 5.9 Transfer hydrogenation of aromatic aldehydes with HCOONa in water. ... 

Carbon-Nitrogen Bond Formation Based on Hydrogen Transfer... 

The cyclizahon of amino alcohols should be an attractive method for the synthesis of N-heterocyclic compounds, mainly because they can be obtained in a single step and without the generation of wasteful byproducts. Carbon-nitrogen bond formation catalyzed by Cp lr complexes has been extended to the synthesis of N-hetero-cyclic compounds by the cyclization of amino alcohols. 

Carbon-nitrogen bond formation, by reductive amination, 59, 1 Carbon-phosphorus bond formation, 36, 2 Carbonyl compounds, addition of... 

The reactions are complex, and ordinarily the first step involves carbon-nitrogen bond formation while the final products are the corresponding hydroxamic acids. 

The kinetic and other evidence obtained suggest that the carbon-nitrogen bond formation is the consequence of a nucleophilic interaction of an Af-phenylchlorohydroxylamine intermediate 135, formed in the second reaction step from 134, and the acyl halide, which leads to an Af-acyl-Af-chlorophenylhydroxylamine cation intermediate 136. The latter loses chlorine with the formation of 137. 

In the case of thiocyanogen chloride and thiocyanogen, the formal electrophile is [NCS]+. The presumed intermediate is a cyanosulfonium ion. The thiocyanate anion is an ambident nucleophile, and both carbon-sulfur and carbon-nitrogen bond formation can be observed, depending upon the reaction conditions (see entry 9 in Scheme 4.5). 

Reports on the synthesis of five-membered heterocycles by intramolecular nitrogen—nitrogen bond formation (N1—N5) came some years ago from our laboratory [79CC891 81 JCS(Pl) 1891 83JCS(P1)2273]. Thus, 4-alkyl(aryl)amino-l-azabutadienes 2, which are readily available in large scale from alkyl(aryl)imines 1 and aliphatic or aromatic nitriles (70S 142 ... 

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