Palladium-catalyzed intermolecular alkylation of enamides with [small alpha]-bromo carbonyls was developed. Under mild reaction conditions, various cyclic and acyclic enamides reacted well with [small alpha]-bromo carbonyls to afford the corresponding multi-substituted alkene...
Novel chiralmonodentate phosphorus ligands, SIPHOS, were conveniently synthesized from 1,1‘-spirobiindane-7,7‘-diol. The Rh complexes of SIPHOS can catalyze the hydrogenation of α-dehydroaminoesters in mild conditions, providing α-amino acid derivatives in up to 99% ee. Enamides and β-dehydroamino esters can also be hydrogenated in good to excellent enantioselectivities (up to 99% and 94% ee, respectively)
Enamides were efficiently prepared via a novel Rh/C-catalyzed direct hydroacylation of ketoximes. Up to 88% isolated yield of enamides were obtained with this method. Subsequent asymmetric hydrogenation of the enamides with Rh/DuanPhos complex gave the corresponding chiral amine in excellent enantioselectivities (up to 99.7% ee).
ethynylation reaction between N‐vinylacetamides and (bromoethynyl)triisopropylsilane catalyzed by palladium is reported. A broad scope of cyclic N‐vinylacetamide derivatives was tolerated and the corresponding products could be obtained in acceptable yields. This work provides a general tool for the synthesis of conjugated enyne products using palladium(II) acetate as catalyst. The mild reaction conditions