- Low-temperature Rh-catalyzed asymmetric 1,4-addition of arylboronic acids to α,β-unsaturated carbonyl compounds
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Rhodium-catalyzed asymmetric 1,4-addition of arylboronic acids to α,β-unsaturated carbonyl compounds was achieved at temperatures below 0 C using a Rh/MeO-F12-BIPHEP catalyst. The reaction of cyclohexenone or N-R-maleimide with arylboronic acids proceeded even at -80 C in the presence of the Rh catalyst. In the latter case, high enantioselectivity was observed because a low-temperature method was used, regardless of the type of substituent on maleimide.
- Korenaga, Toshinobu,Ko, Aram,Shimada, Kazuaki
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p. 9975 - 9980
(2013/10/22)
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- Rh-catalyzed asymmetric 1,4-addition of arylboronic acids to α,β-unsaturated ketones with DIFLUORPHOS and SYNPHOS analogues
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Applications of electron-deficient DIFLUORPHOS and SYNPHOS analogues in the rhodium-catalyzed asymmetric conjugate addition of boronic acids to α,β-unsaturated ketones afford the 1,4-addition adducts in yields up to 92% and with 99% ee. Particularly, a Rh-catalyzed asymmetric 1,4-addition of arylboronic acids to nonsubstituted maleimide substrates using the (R)-3,5-diCF3-SYNPHOS ligand is also reported. This protocol provides access to various enantioenriched 3-substituted succinimide units of biological interest, in high yields and good to excellent ee up to 93%, which could be upgraded up to 99% ee, after a single crystallization.
- Berhal, Farouk,Wu, Zi,Genet, Jean-Pierre,Ayad, Tahar,Ratovelomanana-Vidal, Virginie
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experimental part
p. 6320 - 6326
(2011/10/05)
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