From alkenes

The addition of N-bromosuccinimide (1.1equiv) to a dichlo-romethane solution containing the alkene (1 equiv) and cyana-mide (4 equiv). The solution was maintained at room temperature (3 days) and then washed with water, dried, and concentrated in vacuo. Treatment of the bromocyanamide [intermediate] with 1% palladium on charcoal in methanol (1h) led to reduction of the for-madine. Addition of base to the reaction mixture (50% aqueous KOH, reflux 6h) followed by extraction with ether gave monoamine. (Yield is 48-64% final amine from alkenes analogous to safrole)... 

TT-Aliylpalladium chloride reacts with a soft carbon nucleophile such as mal-onate and acetoacetate in DMSO as a coordinating solvent, and facile carbon-carbon bond formation takes place[l2,265], This reaction constitutes the basis of both stoichiometric and catalytic 7r-allylpalladium chemistry. Depending on the way in which 7r-allylpalladium complexes are prepared, the reaction becomes stoichiometric or catalytic. Preparation of the 7r-allylpalladium complexes 298 by the oxidative addition of Pd(0) to various allylic compounds (esters, carbonates etc.), and their reactions with nucleophiles, are catalytic, because Pd(0) is regenerated after the reaction with the nucleophile, and reacts again with allylic compounds. These catalytic reactions are treated in Chapter 4, Section 2. On the other hand, the preparation of the 7r-allyl complexes 299 from alkenes requires Pd(II) salts. The subsequent reaction with the nucleophile forms Pd(0). The whole process consumes Pd(ll), and ends as a stoichiometric process, because the in situ reoxidation of Pd(0) is hardly attainable. These stoichiometric reactions are treated in this section. 

Preparation of Tr-Allylpalladium Complexes from Alkenes and Their Reactions with Carhon Nucleophiles... 

We now have a new problem Where does the necessary alkene come from Alkenes are prepared from alcohols by acid catalyzed dehydration (Section 5 9) or from alkyl halides by dehydrohalogenation (Section 5 14) Because our designated starting material is tert butyl alcohol we can combine its dehydration with bromohydrm formation to give the correct sequence of steps... 

In the laboratory vicinal diols are normally prepared from alkenes using the reagent osmium tetraoxide (OSO4) Osmium tetraoxide reacts rapidly with alkenes to give cyclic osmate esters... 

The following section describes the preparation of epoxides by the base promoted ring closure of vicinal halohydrms Because vicinal halohydrms are customarily prepared from alkenes (Section 6 17) both methods—epoxidation using peroxy acids and ring closure of halohydrms—are based on alkenes as the starting materials for preparing epoxides... 

The formation of vicinal halohydrms from alkenes was described m Section 6 17 Halo hydrins are readily converted to epoxides on treatment with base... 

Many aldehydes and ketones are made m the laboratory from alkenes alkynes arenes and alcohols by reactions that you already know about and are summarized m Table 17 1... 

Oxaziridines unsubstituted at nitrogen as well as some iV-acylated oxaziridines offer synthetic potentialities due to their ability to transfer their nitrogen function to nucleophiles (Section 5.08.3.1.4). The simplicity of preparation of some aziridines from alkenes and the Spiro oxaziridine (S2) equals the simplicity of epoxidation. Aziridine (299), for example, is obtained by simple heating of indene with (52) in toluene (74KGS1629). 

Table 2. gem-Difluorocyclopropanes from Alkenes and Hexafluoropropylene Oxide... 

As a ligand towards metals, C2F4 and other unsaturated fluorocarbons differ markedly from alkenes (p. 931). 

The Hegedus indole synthesis involves one of the earlier (formal) examples of olefin hydroamination. An ortho-vinyl or ortho-nllyl aniline derivative 1 is treated with palladium(II) to deliver an intermediate resulting from alkene aminopalladation. Subsequent reduction and/or isomerization steps then provide the indoline or indole unit 2, respectively. 

A novel one-pot synthesis of ct-nitro ketones from alkenes has been observed 01 with trimethylsilyl nitrate-chromium trioxide or a trimeihylsilyl nitrate-DMSO reagent system fEq. 2.44. ... 

Alkene addition reactions occur widely, both in the laboratory and in living organisms. Although we ve studied only the addition of HX thus far, many closely related reactions also take place. In this chapter, we ll see briefly how alkenes are prepared, we ll discuss many further examples of aJkene addition reactions, and we ll sec the wide variety of compounds that can be made from alkenes. 

Alkenes are reduced by addition of H2 in the presence of a catalyst such as platinum or palladium to yield alkanes, a process called catalytic hydrogenation. Alkenes are also oxidized by reaction with a peroxyacid to give epoxides, which can be converted into lTans-l,2-diols by acid-catalyzed epoxide hydrolysis. The corresponding cis-l,2-diols can be made directly from alkenes by hydroxylation with 0s04. Alkenes can also be cleaved to produce carbonyl compounds by reaction with ozone, followed by reduction with zinc metal. 

Preparing Alkyl Halides from Alkenes Allylic Bromination 339... 

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