- Bifunctional Thiourea-Catalyzed Stereoablative Retro-Sulfa-Michael Reaction: Concise and Diastereoselective Access to Chiral 2,4-Diarylthietanes
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Owing to the chiral recognition capacity of bifunctional thioureas, a stereoablative retro-sulfa-Michael reaction has been developed. Utilization of a biphasic system enabled us to render the process catalytic. The usefulness of this methodology was further illustrated by the diastereoselective synthesis of all possible stereoisomers of 2,4-diarylthiethanes.
- Bacsó, András,Szigeti, Mariann,Varga, Szilárd,Soós, Tibor
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- Acylcobalt Salophen Reagents. Precursors to Acyl Radical Intermediates for Use in Carbon-to-Carbon Bond-forming Reactions to Alkenes
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Acylcobalt salophen reagents (6) are conveniently synthesised from carboxylic acid chlorides following treatment with the sodium derivative (5) produced from reduction of cobalt(II) salophen with sodium amalgam in tetrahydrofuran at room temperature.The acylcobalt salophens (6) undergo homolytic cleavage in the presence of light from a conventional 300 W sunlamp to give acyl radicals (24) which then undergo additions to activated carbon-to-carbon double bonds, leading to enones, viz. (26) , or saturated ketones, viz. (34) .Intramolecular cyclisations of the acylcobalt salophens (42a) and (42b) lead to the ylidenecyclopentanones (43) and (45), respectively.
- Coveney, Donal J.,Patel, Vinod F.,Pattenden, Gerald,Thompson, David M.
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p. 2721 - 2729
(2007/10/02)
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- ACYLCOBALT SALOPHEN REAGENTS. PRECURSORS TO ACYL RADICAL INTERMEDIATES FOR INTER- AND INTRA- MOLECULAR OXIDATIVE MICHAEL ADDITION REACTIONS
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Acylcobalt salophens (2) undergo homolytic cleavage (Δ, sunlamp) producing acyl radicals (10) which undergo oxidative additions to activated carbon-to-carbon double bonds leading to enones and functionalised ring systems e.g. (3)(4);(5)(6);(7)(8);(12)(13); and (14)(15).
- Coveney, Donal J.,Patel, Vinod F.,Pattenden, Gerald
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p. 5949 - 5952
(2007/10/02)
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