Olefin Hydroamination

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. 

Iridium-Catalyzed Olefin Hydroamination (OHA) 151 Table 6.2 Widening the synthetic scope of the CMM system. 

Scheme 6.2 The proposed role of naked fluoride in Ir-catalyzed olefin hydroamination.

More recently chiral organolanthanide precatalysts of the type [Me2SiCp"(R Cp)]LnCH(SiMe3)2 and [Me2SiCp"(R Cp)]LnN(SiMe3)2 (R = ( + )-neomenthyl, (— )-menthyl Ln = Y, La, Sm, Lu) have been used for efficient regio- and enantioselective olefin hydroamination/cyclization processes. For example, a > 95% diasteroselectivity at 15 °C was achieved with... 

The aziridination of olefins, which forms a three-membered nitrogen heterocycle, is one important nitrene transfer reaction. Aziridination shows an advantage over the more classic olefin hydroamination reaction in some syntheses because the three-membered ring that is formed can be further modified. More recently, intramolecular amidation and intermolecular amination of C-H bonds into new C-N bonds has been developed with various metal catalysts. When compared with conventional substitution or nucleophilic addition routes, the direct formation of C-N bonds from C-H bonds reduces the number of synthetic steps and improves overall efficiency.2 After early work on iron, manganese, and copper,6 Muller, Dauban, Dodd, Du Bois, and others developed different dirhodium carboxylate catalyst systems that catalyze C-N bond formation starting from nitrene precursors,7 while Che studied a ruthenium porphyrin catalyst system extensively.8 The rhodium and ruthenium systems are... 

Gribkov, D.V., Hultzsch, K.C., and Hampel, F. (2003) Synthesis and characterization of new biphenolate and binaphtholate rare-earth-metal amido complexes catalysts for asymmetric olefin hydroamination/cyclization. Chemistry - A European Journal, 9, 4796. 

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. 

Figure 5.12. Three step mechanism of olefins hydroamination... 

Thus, N-H bond cleavage in this system provides a foundation for the development of mild catalytic transformation of ammonia as in arene-oxidative amination and olefin hydroamination. 

Simmons B, Walji AM, MacMillan DWC (2009) Cycle-Specific Organocascade Catalysis Application to Olefin Hydroamination, Hydro-oxidation, and Amino-oxidation, and to Natural Product Synthesis. Angew Chem Int Ed 48 4349... 

As noted in the introductory section to amido complexes, early-transition-metal-amido complexes have been used as catalysts for olefin polymerization, and they have been used as catalysts or precatalysts for alkyne and olefin hydroamination, olefin metathesis, - ... 

Enantioselective olefin hydroamination with aniline is catalyzed by Noyori s catalyst, and hydroamination of internal alkynes with primary amines is catalyzed by Cp2TiMc2. 

Simmons, B., Walji, A. M., Mac Millan, D. W. C. (2009). Cycle-specific organocascade catalysis appheation to olefin hydroamination, hydro-oxidation and amino-oxidation and to natural product synthesis. Angewandte Chemie International Edition, 48,4349-4353. 

In consecutive ptq>ers, Maries group have carried out mechanistic work on asymmetric olefin hydroamination using chiral organolantfumides, and the configurational inimeonversions and full structural characterisatitMi of the catalyst precursor conq)Iexes. ... 

Dorta R, Egli P, Ziircher F, Togni A. The [IrClfdiphos-phine)]2/fluoride system. Developing catalytic asymmetric olefin hydroamination. J. Am. Chem. Soc. 1997 19(44) 10857-10858. 

Fig. 5.12 Three-step mechanism of olefins hydroamination. (From https //upload.wikimeclia.org/ wikipedia/commonsAhumb/5/5a/rhree of the four most comrr on catalytic cycles for hydroamination. tif/k)ssy-page1-1280px-Three of the four most comrrK>n catalytic cycles for hydroamination.tif.jpg).

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