An efficient and general synthesis of alkyl alkynyl sulfoxides

Kabanyane, Sidima; MaGee, David I.

doi:10.1139/v92-350

Cited by 47 publications

(16 citation statements)

References 5 publications

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“…Treatment of 1-hexyne with nBuLi followed by capture with diaryl disulfides afforded alkynyl sulfides 7 a,c,d. [23] At this point, we decided to prepare racemic compounds because their synthesis is slightly shorter than that of the optically pure materials and they were adequate substrates to study the diastereoselectivity of the process. [24] Then, syn Pd-catalyzed hydrostannylation provided vinyl stannanes 8 a,c,d in good yields.…”

Section: Resultsmentioning

confidence: 99%

Asymmetric Claisen Rearrangements on Chiral Vinyl Sulfoxides

Pradilla

Montero

Tortosa

et al. 2008

Chemistry A European J

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Section: Resultsmentioning

confidence: 99%

Asymmetric Claisen Rearrangements on Chiral Vinyl Sulfoxides

Pradilla

Montero

Tortosa

et al. 2008

Chemistry A European J

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“…Acetylenic sulfones 2 a ,41a 2 b ,41a 2 c – f , and 8 41b were obtained by the selenosulfonation and selenoxide elimination of the corresponding acetylenes 42. Sulfone 2 c was kindly provided to us by Dr. H. Zhai, and 2 g 43 was prepared by the meta ‐chloroperoxybenzoic acid (MCPBA) oxidation of the corresponding acetylenic sulfide, which was obtained by the general method of Kabanyane and Magee 44. Terminal acetylenic sulfone 7 was produced by the method of Chen and Trudell 45.…”

Section: Methodsmentioning

confidence: 99%

Indole Synthesis by Conjugate Addition of Anilines to Activated Acetylenes and an Unusual Ligand‐Free Copper(II)‐Mediated Intramolecular Cross‐Coupling

Gao

Back

2012

Chemistry A European J

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A versatile new synthesis of indoles was achieved by the conjugate addition of N-formyl-2-haloanilines to acetylenic sulfones, ketones, and esters followed by a copper-catalyzed intramolecular C-arylation. The conjugate addition step was conducted under exceptionally mild conditions at room temperature in basic, aqueous DMF. Surprisingly, the C-arylation was performed most effectively by employing copper(II) acetate as the catalyst in the absence of external ligands, without the need for protection from air or water. An unusual feature of this process, for the case of acetylenic ketones, is the ability of the initial conjugate-addition product to serve as a ligand for the catalyst, which enables it to participate in the catalysis of its further transformation to the final indole product. Mechanistic studies, including EPR experiments, indicated that copper(II) is reduced to the active copper(I) species by the formate ion that is produced by the base-catalyzed hydrolysis of DMF. This process also served to recycle any copper(II) that was produced by the adventitious oxidation of copper(I), thereby preventing deactivation of the catalyst. Several examples of reactions involving acetylenic sulfones attached to a modified Merrifield resin demonstrated the feasibility of solid-phase synthesis of indoles by using this protocol, and tricyclic products were obtained in one pot by employing acetylenic sulfones that contain chloroalkyl substituents.

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“…Both alkynl and aromatic alkyne are receivable in this protocol. Alkyl halides, which are readily available commercially are generally more varied and cheaper than alkyl thiols or disulfides [12][13][14]. The results are summarized in Table 1.…”

Section: Resultsmentioning

confidence: 99%