Amination of Olefins

Amination of olefins represents interesting reactions (involving nucleophiles) which may have essential practical applications  

This reaction is thermodynamically favorable (for ethylene A 29s = 230). However, it proceeds under unusually drastic conditions. The formation of ethylamine from ethylene and ammonia occurs in the presence of metallic sodium at 473 K and under 40 MPa pressure. At the same temperature, this reaction is also catalyzed by molybdenum oxide. However, the reaction rate is very slow, and at higher temperatures the equilibrium of this reaction is not favorable. 

The platinum(II) ethylene complex stoichiometrically reacts with NH3  

Reactions of secondary amines with alkenes and dienes were also carried out/54,114-116) reactions are significant in organic synthesis, and are catalyzed mainly by palladium, platinum, nickel, and rhodium complexes. 

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Synthesis of the title compound is representative of a number of syntheses of nonaromatic nitrogen heterocycles via Pd(Ill-catalyzed amination of olefins. These tosylated enamines are not readily available by standard synthetic methods, and show potential for further functionalization of the heterocycle. The saturated amine can be synthesized from the title compound by hydrogenation of the double bond followed by photolytic deprotection. ... 

Selenium diimides react in a manner similar to SeOa with unsaturated organic compounds. The first report of BuN=Sc=N Bu described its use as an in situ reagent for allylic amination of olefins and acetylenes. Improved procedures for this process (Eq. 10.5) and for the diamination of 1,3-dienes (Eq. 10.6) have been developed using the reagents RN=Se=NR [R = para-toluenesulfonyl (Ts), ort/io-nitrobenzenesulfonyl (Ns)]. ... 

Reactions of amines with alkenes have been reviewed298,299. Alkali metal amides are active homogeneous catalysts for the amination of olefins. Thus diethylamine and ethylene yield triethylamine when heated at 70-90 °C at 6-10 atm in the presence of lithium diethylamide and /V./V./V. /V -tetrarncthylcthylcncdiaminc. Solutions of caesium amide promote the addition of ammonia to ethylene at 100 °C and 110 atm to give mixtures of mono-, di- and triethylamines300. The iridium(I)-catalysed addition of aniline to norbomene affords the anilinonorbomane 274301. Treatment of norbomene with aniline... 

Some intramolecular aminations of olefins have been reported for solenopsin A (Id) and its isomer (Ic) (389-392). The dimer (200) of methyl vinyl ketone was converted to the ketone (202) by a standard procedure. Borohydride reduction of 202, followed by acid-catalyzed cyclization, yielded an exo/endo (60/40)... 

One simple way for arriving at a photoinduced Markovnikov-type amination of olefins is illustrated in Scheme 3.15, for the case of o-alkenylphenols (e.g., 24). Here, an ammonium salt of the o-alkenylphenolate anion (25) is prepared and irradiated this causes proton transfer within the ion pair (from the amine to the olefin), and the resulting zwitterion undergoes nucleophilic addition of the amine at the benzylic cation center. The addition is selective for N- rather than O-nucleophiles, as shown in the case of ethanolamine [34]. 

Direct amination of olefins is a special case and has been successfully developed for only a few amines. BASF has developed proprietary technology for the direct amination of isobutylene to yield t-butylamine [see Eq. (14.10)], and has been operating a commercial plant in Western Europe since 1993116. 

Pd-Catalyzed intramolecular amination of olefins leading to N-heterocycles 91MI40. 

PHENYLPROPANAL. OSMIUM-CATALYZED VICINAL OXY-AMINATION OF OLEFINS BY CHLORAMINE-T is a novel and useful procedure for the preparation of vicinal hydroxy arylsulfon-amides which in turn can be employed in the synthesis of a host of sub-... 

The direct amination of olefins (hydroamination cf. Section 2.7) has only been achieved efficiently for alkenes with a tertiary carbon atom (e.g., isobutene) or ethylene [6]. Furthermore, the equilibrium of the hydroamination is not favorable in many cases, so first-pass yields can be low with a need for a high recycle stream. 

Sharpless and coworkers have reported a new series of reagents for allylic amination of olefins,79-5 vicinal oxyamination of olefins,76 and 1,2-diamination of 1,3-dienes.77... 

In 1976, Hegedus et al. described the synthesis of indoles using a Pd-assisted intramolecular amination of olefins, which tolerated a range of functionalities [8a, 114]. For example, the requisite o-allylaniline 119 was prepared in high yield by the reaction of 5-methoxy-carbonyl-2-bromoaniline with n-ally I nickel bromide. Addition of 119 to a suspension of stoichiometric PdCl2(CH3CN)2 in THF produced a yellow precipitate (the putative intermediate 121), which upon treatment with Et, N gave rise to indole 120 and deposited metallic palladium. 

Scheme12.5 Aziridination as a side reaction of Rh catalyzed C H amination of olefinic sulfamide.

Additions to multiple bonds catalyzed by radical initiators produce novel synthetic methods. Carboxylic acids add to acetylenic compounds in the presence of organic peroxides. Acetic acid and acetylene yield adipic acid 1-hexyne and acetic acid give octen-3-oic acid. Radical amination of olefins with hydroxylamine sulfonic acid and hydroxylamine in the presence of FeCla gives the corresponding l-amino-2-chloro compounds. ... 

Table 3. Homolytic amination of olefinic compounds with protonated N Olefinic substrate N-Chloroamine Initiator Time (min) Adduct...

Moreover, there are already two other oxidative amination processes on the horizon, namely allylic amination of olefins and 1,2-diamination of 1,3-dienes [14]. Could these useful, but stochiometric transformations be rendered catalytic and perhaps also asymmetric some day ... 

He also pioneered the osmium-catalyzed vicinal aminohydroxylation reaction (AH), where imido osmium complexes react with olefins to form p-aminoalcohols [18]. Closely related to the DH and AH reactions is the amination of olefins leading to vicinal diamines, which was explored by Sharpless [19, 20] and Muniz [21, 22]. 

Af-Substituted aziridines (55) can be synthesized by the palladium-promoted amination of olefins using primary amines followed by oxidation with bromine. ... 

Scheme 8.11 Amination of olefins catalysed by a nickel(ll) complex.

Oxidative aminations of olefins with sulfonamides also appear to occur by insertions of alkenes into Pd-N bonds in some cases. An example of the use of stereochemistry to probe for syn or anti addition of palladium and nitrogen aaoss an alkene during oxidative amination is shown in Equation 9.89b. The stereochemistry of the alkene unit indicates that the reactions occur by insertions of olefins into Pd-N bonds. As shown in Equation 9.89b, frie E-olefin containing a pendant sulfonamide would form the E-product if syn addition of the palladium and sulfonamido group occurs during the catalytic process, but it would form the Z-product if anti addition occurred. The product from syn addition is formed, and such syn stereochemistry is consistent with migratory insertion of the olefin into a palladium-sulfonamido intermediate. ... 

This chapter focuses on the subset of these reactions that have been studied most intensively and that draw from the stoichiometric reactions presented earlier in this text. Thus, the first sections of this chapter highlight certain aspects of hydrocyanation, hydrosilylation, disilylation, hydroboration, diboration, silylborations, and hydroami-nation. The last section presents aspects of palladium-catalyzed oxidation and metal-catalyzed oxidative amination of olefins. 

The oxidative aminations of olefins have been reported in parallel witfi the oxidations of olefins witii alcohols, phenols, and carboxylic acids. These reactions are generally conducted with amides or imides amines are tfiought to be protonated by the acidic medium or to bind the metal center too tightly to allow for the catalytic chemistry to occur. Some exceptions noted below have been observed with arylamines or with rhodium catalysts. These oxidations have been conducted botfi intermolecularly and intramolecularly The oxidations have been conducted with benzoquinone, with copper, or with alone as the... 

Some of the earliest oxidative aminations of olefins were reactions of lactams with electron-poor olefins reported by Murahashi. Examples of these reactions conducted with tiie combination of Oj and CuCl with HMPA as additive are shown in Equation 16.115. This type of oxidative amination of olefins can also be conducted with N-alkyl arylamines, as demonstrated by Hegedus (Equation 16.116). Like the oxidations of acrylates with alcohols, these reactions occur at the p-carbon of the acrylate. 

Intramolecular oxidative aminations of olefins have alsobeen studied, and many of these intramolecular processes were observed prior to the analogous intermolecular variants. The oxidative aminations of alkenes with arylamines and arylamine derivatives catalyzed by palladium complexes were shown by Hegedus to form indoles (Equation 16.120). These reactions were conducted with orf/io-allylaniline and ort/zo-allylaniline derivatives as substrate, Pd(NCMe)jCl2 as catalyst, and benzoquinone as oxidant. Intramolecular reactions of N-tosylated aliphatic amines were reported by Larock. ° For example, the tosylamide in Equation 16.121 imdergoes cyclization in high yield in the presence of dioxygen with Pd(OAc)j as catalyst in DMSO. A related reaction (Equation 16.122) was reported recently in toluene solvent with added pyridine. ... 

The feasibility of a synthetic approach for solid-phase assembly of aliphatic polyamine dendritic structures via tandem hydroformylation/reductive amination of olefins and phthalimide protecting group removal was demonstrated by Eilbracht and Kop. " However,... 

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