Catalytic Asymmetric Allylic Amination with Isatins, Sulfonamides, Imides, Amines, and <i>N</i>-Heterocycles
作者:Ciarán C. Lynch、Kaluvu Balaraman、Christian Wolf
DOI:10.1021/acs.orglett.0c00936
日期:2020.4.17
A generally useful palladium-catalyzed method for the asymmetricallylicamination with a large variety of isatins, sulfonamides, imides, amines, and N-heterocycles is introduced. A single protocol with a readily available catalyst accomplishes this reaction at room temperature with high yields and enantioselectivities often exceeding 90%, which is demonstrated with 31 examples.
Synthesis and applications to asymmetric catalysis of a series of mono- and bis(diazaphospholidine) ligands
作者:Donald Smyth、Heather Tye、Colin Eldred、Nathaniel W. Alcock、Martin Wills
DOI:10.1039/b106399p
日期:2001.11.1
The synthesis of a series of closely related mono- and bis(diazaphospholidine) ligands has been achieved using the condensation of a diamine with a bis(dimethylamino)arylphosphine. The resulting ligands have given excellent results in palladium-catalysed allylic substitution reactions to form C–C bonds (up to 89% ee) and C–N bonds (up to 78% ee).
An efficient synthetic route to chiral allylic amines has been developed by nickel/(S,S)-Ph-BPE complex catalyzed chemoselective asymmetrichydrogenation of α,β-unsaturated ketoimines. Varieties of α,β-unsaturated ketoimines have been well tolerated in this transformation to give chiral allylic amines with high yields and excellent ee values (up to 99% yield, up to 99% ee). A gram-scale reaction with
chiral super Brønsted C–H acids, BINOL-derived phosphoryl bis((trifluoromethyl)sulfonyl) methanes (BPTMs), were developed. As compared to widely utilized BINOL-derived chiral phosphoric acids (BPAs) and N-triflyl phosphoramides (NTPAs), BPTMs displayed much higher Brønsted acidity, resulting in dramatically improved activity and excellent enantioselectivity as demonstrated in catalytic asymmetric Mukaiyama–Mannich
Ferrocenyl-QUINAP: a planar chiral P,N-ligand for palladium-catalyzed allylic substitution reactions
作者:Ralf J. Kloetzing、Paul Knochel
DOI:10.1016/j.tetasy.2005.12.001
日期:2006.1
The new planar chiral P,N-ligands 1a and 1b were prepared via a straightforward enantioselective synthesis using a Negishi cross-coupling and a sulfoxide/lithium exchange. Ligand 1a was successfully applied to Pd-catalyzed allylic alkylation (86% ee) and amination (83% ee) reactions.