Iron-Catalyzed Tunable and Site-Selective Olefin Transposition
作者:Xiaolong Yu、Haonan Zhao、Ping Li、Ming Joo Koh
DOI:10.1021/jacs.0c08631
日期:2020.10.21
earth-abundant iron-based complex, a base and a boryl compound promote efficient and controllable alkene transposition. Mechanistic investigations reveal that these processes likely involve in situ formation of an iron-hydride species which promotes olefin isomerization through sequential olefin insertion/β-hydride elimination. Through this strategy, regiodivergent access to different products from
CC 双键的催化异构化是必不可少的化学转化,用于提供更高价值的类似物,在化学工业中具有重要用途。尽管在该领域取得了进展,但仍然迫切需要一种通用催化解决方案,能够精确控制环状和非环状体系中的 C=C 键迁移位置,以提供二取代和三取代烯烃。在这里,我们展示了催化量的合适的地球丰富的铁基络合物、碱和硼基化合物促进有效和可控的烯烃转位。机理研究表明,这些过程可能涉及原位形成铁氢化物物种,该物种通过顺序烯烃插入/β-氢化物消除促进烯烃异构化。通过这个策略,
Cobalt-Catalyzed Isomerization of 1-Alkenes to (<i>E</i>)-2-Alkenes with Dimethylphenylsilylmethylmagnesium Chloride and Its Application to the Stereoselective Synthesis of (<i>E</i>)-Alkenylsilanes
“Co”axing selectivity into isomerization: Treatment of 1‐alkenes with dimethylphenylsilylmethylmagnesium chloride in the presence of a cobalt‐NHC complex in dioxane at 50 °C or higher provides the corresponding (E)‐2‐alkenes selectively. The isomerization is applicable to the stereoselective synthesis of (E)‐crotylsilanes and (E)‐1‐propenylsilanes from the corresponding homoallylsilanes and allylsilanes
Extracyclic Stereocontrol in Addition Reaction of Crotylsilanes with 2-Substituted 2-Cyclopentenones. Stereodivergent Synthesis of (+)-Neonepetalactone and (+)-Isoneoneptalactone
作者:Li-Rui Pan、Takashi Tokoroyama
DOI:10.1246/cl.1990.1999
日期:1990.11
The additionreaction of E- and Z-crotylsilanes with 2-substituted 2-cyclopentenones showed the preference of erythro and threo products respectively. The refinement of the selectivity was investigated and the result was utilized for efficient syntheses of the title natural products.
Selective synthesis of (E)-crotylsilanes by reaction of crotylmagnesium bromide with hydrosilanes in the presence of dichloro[1,1′-bis(diphenylphosphino)ferrocene]nickel(II)
作者:Tamio Hayashi、Keiji Kabeta、Makoto Kumada
DOI:10.1016/s0040-4039(01)80196-9
日期:——
Dichloro[1,1′-bis(diphenylphosphino)ferrocene]nickel(II) was found to be an effective catalyst for the reaction of crotylmagnesium bromide with hydrosilanes to give (E)-crotylsilanes selectively.