Nitrogen atoms olefins

Ritter Reaction (Method 4). A small but important class of amines are manufactured by the Ritter reaction. These are the amines in which the nitrogen atom is adjacent to a tertiary alkyl group. In the Ritter reaction a substituted olefin such as isobutylene reacts with hydrogen cyanide under acidic conditions (12). The resulting formamide is then hydroly2ed to the parent primary amine. Typically sulfuric acid is used in this transformation of an olefin to an amine. Stoichiometric quantities of sulfate salts are produced along with the desired amine. 

Nitrite ion, an ainbident nucleophile in aprotic solvents, favors nitrogen atom attack on the double bond of various fluoro(halo)olefins. 2-Monohydroperfluoro-nitroalkanes can thus be produced [5] (equation 5)... 

Fluorocylatwn of enarnines and enamides has been intensively studied by different groups [78, 79, 80 SI] The effectiveness of this particular electrophilic substitution reaction becomes obvious when the nitrogen atom of the enamine moiety is engaged in an aromatic system [82 S3] or when the olefinic system is part of an aromatic nucleus [84] (equations 37 and 38) A further extension of this reaction is demonstrated by the tnfluoracetylation of aldehyde dialkyl hydrazones [S5 86] (equation 39)... 

Imide-terminated telechelics are also synthesized by metathesis depolymerization, and it is found that phthalimide-substituted olefins allow for productive depolymerization when only one methylene spacer separates the nitrogen atom and the olefin (Fig. 8.21). This combination of steric hindrance around the nitrogen lone pair and decreased electron donation from resonance prevents the negative neighboring group effect. However, secondary acyclic amines are unable to produce telechelics through metathesis depolymerization because of unfavorable catalyst-amine interactions. 

Keywords Facial selection. Orbital phase, Secondary orbital interaction. Orbital unsymmetrization. Ketones, Olefins, Diels-Alder dienophiles, Diels-Alder dienes, Michael acceptor. Amine nitrogen atom... 

The first metal-catalyzed nitrogen atom-transfer process was reported by Kwart and Khan, who demonstrated that copper powder promoted the decomposition of benzenesulfonyl azide when heated in cyclohexene.280 Evans has demonstrated that Cu(i) and Cu(n) triflate and perchlorate salts are efficient catalysts for the aziridination of olefins employing TsN=IPh as the nitrene precursor.281 Subsequent to this finding, intensive effort has focused on the identification of... 

The carbonylation of the sp3 C-H bond adjacent to a nitrogen atom is also possible by means of chelation-assisted C-H bond activation.121 The carbonylation reaction of A-(2-pyridyl)pyrrolidine occurs at the a-position of the pyrrolidine ring by using [RhCl(cod)]2 as a catalyst and 2-propanol as a solvent. Cyclic amines exhibit a high reactivity (up to 84%) (Equation (93)), while acyclic amines show relatively low reactivity (18%). The use of Ru3(CO)i2 as a catalyst does not result in a carbonylation reaction, but instead the addition of the sp3 C-H bond across the olefin bond to give an alkylation product, as mentioned before (Section 10.05.4). 

Hegedus proposed the probable course of the cyclization reaction, which follows a Wacker-type reaction mechanism. Coordination of the olefin to Pd(II) results in precipitate 110, which upon treatment with Et3N undergoes intramolecular amination to afford intermediate 111. As expected, the nitrogen atom attack occurs in a 5-exo-trig fashion to afford 112. Hydride... 

The asymmetric synthesis of (+)-Codeine 432 devised by White and colleagues included a Beckmann rearrangement to introduce the nitrogen atom in the carbocyclic structure (equation 182). Even though two isomeric lactams 430 and 431 were obtained as a result of the rearrangement, the preferential migration of the bridgehead carbon atom produced 430 as the predominant isomer. The synthesis of the non-natural enantiomer of Codeine was completed after oxidation, olefin formation and reduction. 

Aziridines not substituted on the nitrogen atom react with nitrous acid to produce olefins.324 An N-nitroso compound is an intermediate (2-51) other reagents that produce such intermediates also give olefins. The reaction is stereospecific cis aziridines give cis olefins and trans aziridines give trans olefins.325 Aziridines carrying N-alkyl substituents can be converted to olefins by treatment with ferrous iodide326 or with m-chloroperbenzoic acid.327 An N-oxide intermediate (9-28) is presumably involved in the latter case. 

These generally bind to enzyme that produces them and destroy or inhibit it. For example, olefins and acetylenes bind to nitrogen atoms in the pyrrole part of cytochrome P-450. This may lead to the release of the Fe and destruction of the enzyme. The intermediate can be detected as bound to the enzyme protein or active site. 

The mechanism involving simple nitrogen-coordinated complexes also accounts for reactivities of certain sterically constrained systems. For instance, 3-(diethyamino)cyclohexene undergoes facile isomerization by the action of the BINAP-Rh catalyst (Scheme 18). The atomic arrangement of the substrate is ideal for the mechanism to involve a three-centered transition state for the C—H oxidative addition to produce the cyclometalated intermediate. The high reactivity of this cyclic substrate does not permit any other mechanisms that start from Rh-allylamine chelate complexes in which both the nitrogen and olefinic bond interact with the metallic center. On the other hand, fro/tt-3-(diethylamino)-4-isopropyl-l-methylcyclohexene is inert to the catalysis, because substantial I strain develops during the transition state of the C—H oxidative addition to Rh. 

It is of some interest to speculate briefly oonocming the nature of the peracid-imine reaction. It xb quite possible that this reaction is analogous to the epoxidation of olefins with peracids and involves a similar oydks transition state (X). An equally attractive if less obvious possibility is that the imine reaction proceeds through addition of the peracid to the azomethine followed by internal nucleophilic displace ment of the basic nitrogen atom on the peroxide bond. This reaction... 

Using intramolecular Diels-Alder reactions, Lease and Shea130 have prepared a series of bridgehead olefins, which at the same time are bridgehead lactams with the nitrogen atom at the other bridgehead (30). In these, the C=C double bond and the amide bond are subject to the same kind of distortion. The distortions decrease in the series 30a-30c. 

---