Monodentate Phosphorus Ligand-Enabled General Palladium-Catalyzed Allylic C–H Alkylation of Terminal Alkenes
作者:Lian-Feng Fan、Pu-Sheng Wang、Liu-Zhu Gong
DOI:10.1021/acs.orglett.9b02325
日期:2019.9.6
enable the palladium-catalyzed allylic C-H alkylationreaction of terminal alkenes with a wide variety of carbon nucleophiles. Moreover, an asymmetricallylic C-H alkylation of terminal alkenes with pyrazol-5-ones has been established in the presence of chiral phosphoramidite ligand and chiral phosphoric acid as co-catalyst. Mechanisticstudies suggest that a ternary Pd(0) complex, coordinated with a
Squaramide-catalysed enantioselective Michael addition of pyrazolin-5-ones to nitroalkenes
作者:Jun-Hua Li、Da-Ming Du
DOI:10.1039/c3ob41045e
日期:——
An efficient chiral squaramide-catalysed enantioselective Michael addition of pyrazolin-5-ones to nitroalkenes has been developed. This reaction afforded the chiral pyrazol-3-ol derivatives in high to excellent yields (up to >99%) with high enantioselectivities (up to 94% ee) for most substrates under very low catalyst loading (0.25 mol%). This catalytic asymmetric reaction provides valuable and easy access to chiral pyrazol-3-ol derivatives, which possess potential pharmaceutical activity.
Highly Enantioselective Allylic C–H Alkylation of Terminal Olefins with Pyrazol-5-ones Enabled by Cooperative Catalysis of Palladium Complex and Brønsted Acid
作者:Hua-Chen Lin、Pu-Sheng Wang、Zhong-Lin Tao、Yu-Gen Chen、Zhi-Yong Han、Liu-Zhu Gong
DOI:10.1021/jacs.6b08236
日期:2016.11.2
A highly enantioselective allylic C-H alkylation reaction of allylarenes with pyrazol-5-ones has been established by the cooperative catalysis of a chiral palladium complex and chiral Brønsted acid to afford a wide spectrum of functionalized chiral N-heterocycles with an all-carbon quaternary stereogenic center in high yields and with high levels of enantioselectivity (up to 96% ee), wherein the chiral
A practical and tunable transition-metal-free aerobic oxidation of pyrazol-5-ones preparing either 4-hydroxypyrazoles (via C–H hydroxylation) or bispyrazoles (via dehydrogenative homocoupling) is described. The K2CO3/dioxane reagent system predominately promoted hydroxylation to deliver the α-hydroxylated pyrazoles. In contrast, the formation of bispyrazoles was overwhelmingly preferred with CH3CN
介绍了一种实用且可调谐的吡唑-5-酮无过渡金属好氧氧化方法,可制备4-羟基吡唑(通过CH羟基化)或双吡唑(通过脱氢均偶联)。K 2 CO 3 /二恶烷试剂系统主要促进羟基化以递送α-羟基化的吡唑。相反,在没有任何添加剂的情况下,以CH 3 CN作为反应介质,双吡唑的形成是绝对优选的。