Solvent-controlled direct radical oxyphosphorylation of styrenes mediated by Manganese(III)
作者:Guo-Yu Zhang、Cheng-Kun Li、Da-Peng Li、Run-Sheng Zeng、Adedamola Shoberu、Jian-Ping Zou
DOI:10.1016/j.tet.2016.04.013
日期:2016.6
Direct radical oxyphosphorylation of styrenes with diarylphosphine oxides and dialkylphosphites mediated by Mn(OAc)3 is described. The solvent played a key role in this selective difunctionalization reaction.
Extending the Scope of a Known Furan Synthesis - A Novel Route to 1,2,4-Trisubstituted Pyrroles
作者:Marko Friedrich、Andreas Wächtler、Armin de Meijere
DOI:10.1055/s-2002-22707
日期:——
2-(Acylmethylene)propanediol diacetates, which cyclize readily under acidic conditions to give furans (76-84%) react with primary amines under palladium catalysis to give 1,2,4-trisubstituted pyrroles in moderate to good yields (39-53%). When glycine methyl ester is used as the amine, substituted methyl pyrrol-1-ylacetates (31-82%) are obtained.
Highly effective asymmetrichydrogenation of β-ketophosphonates in the presence of Ru–(S)-SunPhos as catalyst was realized; good to excellent enantioselectivities (up to 99.9% ee) and excellent diastereoselectivities (96:4) were obtained.
The highly chemo- and enantioselective hydrogenation of (E)-2-substituted-4-oxo-2-alkenoic acids was established for the first time using the Rh/JosiPhos complex, affording a series of chiral α-substituted-γ-keto acids with excellent results (up to 99% yield and >99% ee) and high efficiency (up to 3000 TON). In addition, the importance of this methodology was further demonstrated by a concise and gram-scale
Dynamic kinetic resolution of various α-amido-β-keto phosphonates via asymmetrichydrogenation proceeded efficiently to give the corresponding β-hydroxy-α-amido phosphonates in high diastereo- and enantioselectivities (up to 99:1 syn/anti, 99.8% ee). The addition of catalytic amounts of CeCl3·7H2O is necessary to achieve both good selectivity and catalytic efficiency under mild reaction conditions