Highly Enantioselective Conjugate Addition of Thioglycolate to Chalcones Catalyzed by Lanthanum: Low Catalyst Loading and Remarkable Chiral Amplification
Ramping it up: The titled reaction has been developed using a chiral N,N′‐dioxide–LaIII complex as the catalyst. The reaction proceeded with high yield and enantioselectivity. Remarkably, a high asymmetric amplification was observed, as 98 % ee was achieved using 1 mol % L/La(OTf)3 in which the ee value of L was 2 % ee. Tf=trifluoromethanesulfonyl.
Magnesium‐Catalyzed Asymmetric Thia‐Michael Addition to α,β‐Unsaturated Ketones
作者:Joanna A. Jaszczewska‐Adamczak、Paulina Baczewska、Robert Bujok、Jacek Mlynarski
DOI:10.1002/adsc.202301414
日期:2024.3.19
chiral magnesium complexes in an asymmetric carbon-sulfur bond-forming reaction. Enantioselective and cost-effective methodology under mild condition for the thia-Michael addition, utilizing an in situ generated chiral dinuclear magnesium-ProPhenol complex, has been developed. The versatility of this protocol is demonstrated with a broad range of thiol nucleophiles and a wide selection of enones. Enantioenriched
Enantioselective sulfa-Michael addition reaction of methyl thioglycolate to chalcones derivatives with sterically encumbered quinine squaramide organocatalyst
作者:Deniz Hasılcıoğulları、Cihangir Tanyeli
DOI:10.1016/j.tetlet.2018.02.068
日期:2018.4
Asymmetricorganocatalytic sulfa-Michael reactions give access to enantiomerically enriched sulfur containing adducts that can be used as valuable chiral building blocks. A variety of chalcone derivatives were allowed to react with methyl thioglycolate under optimized conditions, in the presence of a bifunctional quinine derived sterically encumbered squaramide organocatalyst, giving rise to excellent