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Nozaki-Hiyama-Kishi

The multi-component procedure is also effective for the chromium-catalyzed addition of organic halides to aldehydes (the Nozaki-Hiyama-Kishi reaction) [73]. The active Cr(II) species is recycled by redox interaction with Mn powder as the stoichiometric co-reductant in the presence of MesSiCl (Scheme 34), which mainly liberates the chromium catalyst from the alkoxide adduct. The chemo- and diastereo-selective addition reaction is performed with a variety of organic halides and alkenyl triflates. In the case of crotyl bromide, the addition is highly stereoconvergent, i.e., the respective anti-... [Pg.81]

Grigg and coworkers developed bimetallic domino reactions such as the electro-chemically driven Pd/Cr Nozaki-Hiyama-Kishi reaction [69], the Pd/In Barbier-type allylation [70], Heck/Tsuji-Trost reaction/1,3 dipolar cycloaddition [71], the Heck reaction/metathesis [72], and several other processes [73-75]. A first example for an anion capture approach, which was performed on solid phase, is the reaction of 6/1-134 and 6/1-135 in the presence of CO and piperidine to give 6/1-136. Liberation from solid phase was achieved with HF, leading to 6/1-137 (Scheme 6/1.30) [76]. [Pg.382]

Nozaki-Hiyama-Kishi (NHK) reactions215,216 are well known and often employed as a useful method for the synthesis of natural products by coupling of allyl, alkenyl, alkynyl, and aryl halides or triflates with aldehydes. The organochromium reagents are prepared from the corresponding halides or triflates and chromium(ll) chloride, and are employed in polar aprotic solvents (THF, DMF, DMSO, etc.). Subsequently, it was found that nickel salts exhibited a significant catalytic effect on the formation of the C-Cr bond217,218 (Equation (19)). [Pg.431]

For a review encompassing the Nozaki-Hiyama-Kishi reaction, see Marshall, J. A. McNulty, L. M. Chemtracts 1997, 10, 50-52. [Pg.532]

Nozaki-Hiyama-Kishi-type reactions to construct a fluoroolefin... [Pg.699]

G. Dutheuil, X. Lei, X. Pannecoucke, J.C. Quirion, A novel diastereoselective synthesis of (Z)-fluoroalkenes via a Nozaki-Hiyama-Kishi-Type reaction, J. Org. Chem. 70 (2005) 1911-1914. [Pg.732]

Threc-carbon ring expansion was carried out in two stages. First, two-carbon homologation of the exo methylene ketone 8 followed by trapping of the intermediate enolate as the triflate led to 9. Nozaki-Hiyama-Kishi coupling followed by acetylation smoothly converted 9 into 10. [Pg.156]

The Nozaki-Hiyama Kishi reaction has been successfully utilized in the total synthesis of palytoxin (355) [170] brefeldin (356) [172], halichondrin B [173], brevetoxin [174], pinnatoxin A [174a] and others. The coupling of alkynyl iodides with aldehydes can be carried out smoothly using CrCl2 and 0.01% of NiCk... [Pg.75]

Chromium. Similar chlorosilane-mediated catalytic processes can be envisaged with many other early transition metals. The development of the first Nozaki-Hiyama-Kishi reactions catalyzed by chromium species [13] illustrates how to avoid the use of an excess of a physiologically suspect and rather expensive salt without compromising the efficiency, practicality and scope of the reaction. The tentative catalytic cycle is depicted in Scheme 3. [Pg.125]

Scheme 3. Proposed catalytic cycle for the first Nozaki-Hiyama-Kishi reactions catalyzed by chromium species. Scheme 3. Proposed catalytic cycle for the first Nozaki-Hiyama-Kishi reactions catalyzed by chromium species.
Scheme 5. An electrochemically driven Nozaki-Hiyama-Kishi reaction. Scheme 5. An electrochemically driven Nozaki-Hiyama-Kishi reaction.
For recent applications of this multicomponent system to other Nozaki-Hiyama-Kishi reactions catalytic in chromium see a) With acrolein acetals R. K. Boeckman, R. A. Hudack, J. Org. Chem. 1998, 63, 3524-3525 b) With trichloroethane J. R. Falek, D. K. Barma, C. Mioskowski, T. Sehlama, Tetrahedron Lett. 1999, 40, 2091-2094 e) CrC cat., TMSCl, NiClj cat., Al-powder M. Kuro-boshi, M. Tanaka, S. Kishimoto, K. Goto, H. Tanaka, S. Torii, Tetrahedron Lett. 1999,40,2785 - 2788. [Pg.129]

Many catalytic reactions are not sensitive to the presence of a sulfur atom on the substrate. Two examples can be quoted the Nozaki-Hiyama-Kishi reaction where a chlorosilane-mediated Cr-Mn-catalyzed C-C coupling occurs between a halogenoalkene and an aldehyde [63], and the [IrCl(CO)3]-catalyzed intramolecular allyl transfer in functionalized 1,3-thiozanes [64]. [Pg.848]

Coupling of vinyl iodide 82 (a substrate derived from geraniol) with aldehyde 84 was accomplished via a Nozaki-Hiyama-Kishi [56] coupling reaction to give 107 after oxidation (Scheme 24). Three straightforward transformations allowed the authors to isolate thyrsiferol (1) and thyrsiferol 23-acetate (4) in a total of 36 steps and 24 steps for the longest linear sequence. [Pg.36]

We selected the natural product thyrsiferol as an ideal target to test our ideas. Its total synthesis was envisioned to proceed as illustrated in the Scheme 28. The successful coupling between aldehyde 84 and vinyl iodide 82 via a Nozaki-Hiyama-Kishi (NHK) reaction [66] had been demonstrated previously [29]. We therefore sought to model our final steps after precedence presented by Forsyth for the union of these two fragments. The focus of our synthetic strategy centered around the stereoselective synthesis of the ABC framework (84) of thyrsiferol (1) as a scaffold to validate the scope of the Cp2TiCl reaction with epoxides toward the assembly of Q-C-glycosides and cyclic ethers. [Pg.40]

With substrates 82 and 137 in hand, the stage was set for the Nozaki-Hiyama-Kishi reaction it was performed using CrCli and 0.1% NiCh in dry DMSO. Under these mild and chemoselective conditions, a diastereomeric mixture of alcohols 138 was obtained in a 37% yield. Further optimization of these reaction conditions was not investigated due to the small quantity of substrate available. [Pg.47]


See other pages where Nozaki-Hiyama-Kishi is mentioned: [Pg.188]    [Pg.494]    [Pg.303]    [Pg.432]    [Pg.303]    [Pg.449]    [Pg.468]    [Pg.466]    [Pg.73]    [Pg.275]    [Pg.26]    [Pg.281]    [Pg.126]    [Pg.129]    [Pg.412]    [Pg.292]    [Pg.303]    [Pg.199]    [Pg.318]    [Pg.319]   
See also in sourсe #XX -- [ Pg.41 ]




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Aldehydes Nozaki-Hiyama-Kishi reaction

Allylation Nozaki-Hiyama-Kishi reaction

Chromium catalysts, Nozaki-Hiyama-Kishi

Chromium catalysts, Nozaki-Hiyama-Kishi reaction

Cyclization, Nozaki-Hiyama-Kishi reaction

Hiyama

Hiyama-Nozaki-Kishi coupling

Intramolecular Nozaki-Hiyama-Kishi

Intramolecular Nozaki-Hiyama-Kishi reaction

Ketones Nozaki-Hiyama-Kishi reaction

Kishi

Natural products Nozaki-Hiyama-Kishi reaction

Nozaki

Nozaki-Hiyama-Kishi conditions

Nozaki-Hiyama-Kishi coupling strategy

Nozaki-Hiyama-Kishi reaction

Nozaki-Hiyama-Kishi reaction chromium complexes

Nozaki-Hiyama-Kishi reaction development

Nozaki-Hiyama-Kishi reaction diastereoselectivity

Nozaki-Hiyama-Kishi reaction enantioselectivity

Oxazoline ligands, Nozaki-Hiyama-Kishi

Oxazoline ligands, Nozaki-Hiyama-Kishi reaction

Stereoselective synthesis Nozaki-Hiyama-Kishi

Vinyl iodide, Nozaki-Hiyama-Kishi

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