2- ethene, reaction with amines

The reactivity of the ethenediazonium salt 9.100 towards the nucleophiles mentioned shows that it has the properties of the corresponding carbocation, since it can ethylate the nucleophile and is prone to attack at the C()ff)-atom of the original ethene-l-diazonium ion. The thermal decomposition pattern is typical of that for an oxonium salt. Reactions with amines are similar to those of ketene acetals. No product that could be explained in terms of an azo coupling reaction, e.g., with 2-naphthol, could be observed. The electrophilicity of the diazonio group is, therefore, low. N-Azo coupling products with azide ions have been postulated with good arguments, however, by Kirmse and Schnurr (1977) with certain short-lived ethene diazonium intermediates produced from nitroso oxazolidones. 

Building the imidazole ring of 385 was achieved by reaction of the 2-(glycofuranosyl)-2-isocyano-2-(4-tolylsulfonyloxy)ethene 384 with amines [95JCS(P1)3029] (Scheme 92). 

Reactions between KCH2SiMe3 and cyclohexene or methylcyclohexene gave white solids formulated as 59 or 60. They were characterized by reaction with CHzO and oxidized with (COCl)2, but no structural data have been reported. Reactions with cyclooctene were similar.45 The role of tertiary amine in the metallation of ethene, n-hexene, and a-pinene has been studied.15... 

Though this review focus on homogeneous catalyzed reactions between unsatured hydrocarbons and carbon dioxide, also some related reactions without transition metal catalysts will be considered. It appears suitable to compare the different possibilities of catalytic and non-catalytic methods in the field of C-C linkage. For instance ionic reactions are well known routes to attach CO2 on a hydrocarbon chain. Living oligomers of ethene obtained with n-BuLi complexed by tertiary amines react with carbon dioxide and yield long-chain car xylic acids [27] (Equation 3). 

With primary or secondary amines, chlorosulfonic acid yields the corresponding sulfamic acid (Equation 5) this reaction with cyclohexylamine afforded the artificial sweetener sodium cyclamate 3 (Equation 9). In contrast to alkanes, alkenes readily react with chlorosulfonic acid to give the alkyl chlorosulfonates thus ethylene (ethene) is absorbed by chlorosulfonic acid to give ethyl chlorosul-fonate 4 (Equation 10). 

The alkylation of the sp3 C-H bonds adjacent to a heteroatom becomes more practical when the chelation assistance exists in the reaction system. The ruthenium-catalyzed alkylation of the sp3, C-H bond occurs in the reaction of benzyl(3-methylpyridin-2-yl)amine with 1-hexene (Equation (30)).35 The coordination of the pyridine nitrogen to the ruthenium complex assists the C-H bond cleavage. The ruthenium-catalyzed alkylation is much improved by use of 2-propanol as a solvent 36 The reaction of 2-(2-pyrrolidyl)pyridine with ethene affords the double alkylation product (Equation (31)). 

Amine oxides are interesting for two reasons. First, amine oxides decompose when strongly heated, and this reaction provides a useful preparation of alkenes. With triethylazane oxide (triethylamine oxide), ethene is formed ... 

Similar to ketones, quinones have also been known for a long time to undergo PET processes with several donors such as aromatic hydrocarbons, olefins and amines etc. [10b, 11]. It is pertinent here to illustrate one of the synthetically important quinone-olefin [186] reactions which has been utilized for the preparation of Benz (a) anthracene 7,12-dione derivatives (237). In the present example, the excited state of naphthaquinone (234) reacts with ethene (235) to give 236, provided the electron transfer is thermodynamically allowed (ca. AGet < 0). In the follow up processes, (236) is transformed to (237) in 30-50% yield. Another report from the same group has described [187] a novel method of photoallylation of naphthaquinone by allyl stannane. 

The reaction of vinyl-substituted silanes and octavinylsilsesquioxane with vinyl-substituted amides, amines (carbazole) as welt as boronates catalyzed by I proceeds effectively to yield under optimum conditions stereo- and/or regio-selectively l-silyl-2-/V- and 1,1-silylboryl-substituted ethenes. 1-silylvinyl carbazole can also be obtained via cross-metathesis of vinylsilane with vinylcarbazole, but only in the presence of the 2nd generation Grubbs catalyst (IV). 

Electron Transfer Processes - A study of the benzophenone/acetonitrile/t-butylamine system has shown that electron transfer occurs from the amine to the excited state benzophenone. Hydrogen abstraction processes within this system ultimately yield the CH2CN radical. When this species is generated in the presence of a diarylethene such as that shown in Scheme 1 then addition affords reasonable yields of the adducts (16). The mode of addition is dictated by the stability of the radical formed on addition to the ethene bond. Addition can also occur to alkenes such as (17) when the adduct (18) is obtained. SET processes also provide a novel synthetic path to 5,6-dihydro-4/f-l,2-oxazines. These reactions involve the DCA-sensitized transformations of the y,5-unsaturated oximes (19). The reactions are carried out in acetonitrile solution with irradiation through Pyrex for no longer than 30 min. This treatment yields the products (20) in reasonable yields. The likely mechanism for the process involves the formation of the intermediate (21) which cyclizes to yield the final products. The reaction is to some extent substituent dependent and when the oxime (19, R = H, R = R = R = Me) is irradiated under the same conditions for 3 h no reaction is... 

The reaction of a simple primary amine, 1-aminocyclopropane, with aqueous lithium hypochlorite takes place readily at room temperature resulting in ring opening. Since the reaction competes with fragmentation to give ethene, the yield of 3-hydroxypropiononitrile, the ring-opened product, is modest (Table 15, entry 5). With 1-amino-1-methylcyclopropane, 4-hy-droxybutan-2-one is formed. 

Heating the diethanolamine or bis(2-chloroethyl)amine hydrochlorides with aniline derivatives gave 1-arylpiperazine derivatives. The 1-substituted piperazines were deuteromethylated. 1,4-Dithiocarbonyl piperazine was obtained from reaction of benzaldehyde with piperazine and sulfur. l,4-Diacetylpiperazine-2,5-dione were reacted with aldehydes to give the monoarylidene products and then 73. 4-Benzylpiperazine-2,5-dione was reacted with bromobenzene to give 74. Diels-Alder cycloaddition of pyrazinone with ethene gave 75 . ... 

The first step consisted of the Mitsunobu etherification of an allyl alcohol with the resorcinol monoester, which afforded 102. Cleavage of the benzoyl protecting group released the phenol, which was then attached to the solid support. One-step cleavage of the THP group and bromination was achieved with PPhs/C Br4 to furnish 103. Nucleophilic substitution of the bromide with benzylamine was followed by acylation of the secondary amine wtith N-Boc-allylglycine 104, which resulted in the precursor 105, ready for the metathesis reaction this was performed with catalyst 101 to yield the final product 106. Either 1-octene or ethene was employed to generate 101. 

Few examples of carboaminations of normal double and triple bonds are known. Similarly to allylic alcohols, tosylated allylic amines with (cthoxy)ethene form 2-ethoxy-4-vinylpyrrolidines 2. The reaction, mediated by stoichiometric amounts of palladium(II) acetate, can be changed to catalytic if copper(II) acetate is added as reoxidant of palladium(O). Moderate stereoselectivity (d.r. 64 36) is reported, however, without further structural assignment. 

Fig. 1. Effect of pretreatment temperature on the catalytic activities of MgO for different types of reactions (9). o 1-butene isomerization at 303 K, A CH4-D2 exchange at 673 K, amination of 1,3-butadiene with dimethylamine at 273 K, hydrogenation of ethene at...

By far the best source for 3a is (trimethylsilyl)diazomethane (19). It has already been mentioned that gas-phase pyrolysis of 19 alone yields products which are derived from intramolecular carbene reactions such as 1,3-C,H insertion and silylcarbene-to-silene rearrangement (see equation 20). Also, copyrolysis of 19 with alcohols or benzaldehyde allowed one to trap the silene but not the carbene 33 (see equation 5). Furthermore, solution photolysis of 19 in the presence of alcohols or amines did not give the X,H insertion products of the carbene but rather trapping products of the silene . On the other hand, photochemically generated carbene 3a did undergo some typical intermolec-ular carbene reactions such as cyclopropanation of alkenes (ethylene, frani-but-2-ene, but not 2,3-dimethylbut-2-ene, tetrafluoroethene and hexafluoropropene), and insertion into Si—H and methyl-C—H bonds (equation 39). The formal carbene dimer, trans-1,2-bis(trimethylsilyl)ethene, was a by-product in all photolyses in the presence of alkenes it is generally assumed that such carbene dimers result from reaction of the carbene with excess diazo compound. 

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