24731-17-7Relevant articles and documents
Synthesis of γ-Haloesters and γ-Ketoesters by Homolytic Addition of Carbon Radicals Generated by α-Haloesters and Triethylborane to Alkenes and Silyl Enol Ethers
Baciocchi, Enrico,Muraglia, Ester
, p. 2763 - 2766 (1994)
An efficient synthesis of γ-haloesters has been achieved, under very mild conditions, by addition of electrophilic carbon radicals CH(R)CO2Et (R=H, Me, CO2Et) generated by XCH(R)CO2Et (X=Br, I)/BEt3/air in DMSO to alkenes and cycloalkenes.The synthesis of γ-ketoesters is also possible when silyl enol ethers are used as the substrates.
Photocontrolled Cobalt Catalysis for Selective Hydroboration of α,β-Unsaturated Ketones
Beltran, Frédéric,Bergamaschi, Enrico,Funes-Ardoiz, Ignacio,Teskey, Christopher J.
, p. 21176 - 21182 (2020/09/17)
Selectivity between 1,2 and 1,4 addition of a nucleophile to an α,β-unsaturated carbonyl compound has classically been modified by the addition of stoichiometric additives to the substrate or reagent to increase their “hard” or “soft” character. Here, we demonstrate a conceptually distinct approach that instead relies on controlling the coordination sphere of a catalyst with visible light. In this way, we bias the reaction down two divergent pathways, giving contrasting products in the catalytic hydroboration of α,β-unsaturated ketones. This includes direct access to previously elusive cyclic enolborates, via 1,4-selective hydroboration, providing a straightforward and stereoselective route to rare syn-aldol products in one-pot. DFT calculations and mechanistic experiments confirm two different mechanisms are operative, underpinning this unusual photocontrolled selectivity switch.
Biocatalytic access to nonracemic γ-oxo esters: Via stereoselective reduction using ene-reductases
Turrini, Nikolaus G.,Cioc, Rǎzvan C.,Van Der Niet, Daan J. H.,Ruijter, Eelco,Orru, Romano V. A.,Hall, Mélanie,Faber, Kurt
, p. 511 - 518 (2017/08/14)
The asymmetric bioreduction of α,β-unsaturated γ-keto esters using ene-reductases from the Old Yellow Enzyme family proceeds with excellent stereoselectivity and high conversion levels, covering a broad range of acyclic and cyclic derivatives. Various strategies were employed to provide access to both enantiomers, which are versatile precursors of bioactive molecules. The regioselectivity of hydride addition on di-activated alkenes was elucidated by isotopic labeling experiments and showed strong preference for the keto moiety as activating/binding group as opposed to the ester. Finally, chemoenzymatic synthesis of (R)-2-(2-oxocyclohexyl)acetic acid was achieved in high ee on a preparative scale combining enzymatic reduction followed by ester hydrogenolysis.
NOVEL COMPOUNDS
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Page/Page column 52, (2015/12/17)
Disclosed are novel retinoid-related orphan receptor gamma (RORγ) modulators and their use in the treatment of diseases mediated by RORγ.
