Palladium-Catalyzed α,β-Dehydrogenation of Esters and Nitriles
摘要:
A highly practical and general palladium-catalyzed methodology for the alpha,beta-dehydrogenation of esters and nitriles is repotted. Generation of a zinc enolate or (cyanoalkyl)zinc species followed by the addition of an allyl oxidant and a palladium catalyst results in synthetically useful yields of alpha,beta-unsaturated esters, lactones, and nitriles. Preliminary mechanistic investigations are consistent with reversible beta-hydride elimination and turnover-limiting, propene-forming reductive elimination.
Cyanation of 1-Halocycloalkenes Catalyzed by Tetracyanocobaltate(I). Convenient Synthesis of 1-Cyanocycloalkenes
作者:Takuzo Funabiki、Hirohito Kishi、Yoshihiro Sato、Satohiro Yoshida
DOI:10.1246/bcsj.56.649
日期:1983.2
1-Cyanocycloalkenes (1-cyanocyclopentene, -hexene, -heptene, and -octene) were readily synthesized by catalytic cyanation of the corresponding 1-halocycloalkenes with tetracyanocobaltate(I). Reactivities of methyl-substituted 1-chlorocyclohexenes were lower than that of 1-chlorocyclohexene, and 1-chloro-2-methylcyclohexene scarecely reacted. Hydrogenation and isomerization of 1-cyanocycloalkenes were
Binaphthol-Based Diphosphite Ligands in Asymmetric Nickel-Catalyzed Hydrocyanation of Styrene and 1,3-Cyclohexadiene: Influence of Steric Properties
作者:Jos Wilting、Michèle Janssen、Christian Müller、Martin Lutz、Anthony L. Spek、Dieter Vogt
DOI:10.1002/adsc.200600315
日期:2007.2.5
(R)-binaphthol-based diphosphite ligands with different substituents was prepared and applied in the asymmetric nickel-catalyzedhydrocyanation of styrene and 1,3-cyclohexadiene to investigate the influence of their steric properties. The optimum steric properties for the hydrocyanation reaction lie within a narrow window. With the optimized ligand, hydrocyanation of styrene gave full conversion (Subs/Ni=100)
制备了一系列具有不同取代基的手性(R)-联萘酚基二亚磷酸酯配体,并将其应用于苯乙烯和1,3-环己二烯的不对称镍催化的氢氰化反应中,以研究其空间特性的影响。氢氰化反应的最佳空间特性在狭窄的窗口内。使用优化的配体,苯乙烯进行氢氰化可得到49%ee的完全转化率(Subs / Ni = 100),TON测为600。1,3-环己二烯的氢氰化可得到50%的转化率(Subs / Ni = 500)。优秀的ee为86%。这表明高ee s不仅可用于乙烯基芳烃,而且可用于不对称镍催化的氢氰化反应中的共轭二烯。
A new conversion of primary nitro compounds into nitriles
作者:Laurent El Kaim、Ariane Gacon
DOI:10.1016/s0040-4039(97)00627-8
日期:1997.5
The reaction of primarynitrocompounds with isocyanides and isocyanates in the presence of a base leads to a new preparation of nitriles. The reaction probably proceeds through the in situ formation of a nitrile oxide followed by a fast oxygen transfer with the isocyanide. Combined with the Knovenagel addition of nitromethane to cyclic ketone, this reaction brings a highly effective regioselective
ONE-POT TRANSFORMATION OF KETONES TO α,β-UNSATURATED NITRILES VIA TRIMETHYLSILOXY NITRILES
作者:Masaji Oda、Akira Yamamuro、Takashi Watabe
DOI:10.1246/cl.1979.1427
日期:1979.12.5
Treatment of ketones with trimethylsilylcyanide in benzene in the presence of a Lewis acid (ZnI2) as a catalyst and subsequent heating after addition of pyridine and phosphoryl chloride have given α,β,-unsaturated nitriles in good yields, providing a general one-pot preparation of α,β,-unsaturated nitriles from ketones.
Nickel‐Catalyzed Reductive Coupling of Vinyl Triflates and 1,4‐Dicyanobenzene to Access Alkenyl Nitriles
作者:Le‐Le Wang、Zhong‐Xian Li、Jun Zhu
DOI:10.1002/adsc.202301072
日期:2024.2.19
We report a vinyl cyanation reaction of vinyl triflates and readily available 1,4-dicyanobenzene through a nickel-catalyzed reductive coupling process. The reaction is operated under mild conditions with remarkable functional-group compatibility. Cyclic vinyl triflates with various ring sizes and substituents at different positions all reacted smoothly. The synthetic utility is demonstrated by the