Isomerization of Terminal Epoxides by a [Pd–H] Catalyst: A Combined Experimental and Theoretical Mechanistic Study
摘要:
An unusual palladium hydride complex has been shown to be a competent catalyst in the isomerization of a variety of terminal and internal epoxides. The reaction displayed broad scope and synthetic utility. Experimental and theoretical evidence are provided for an unprecedented hydride mechanism characterized by two distinct enantio-determining steps. These results hold promise for the development of an enantioselective variant of the reaction.
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 Regioselective Dehydrohalogenation of Alkyl Halides with Dimethylphenylsilylmethylmagnesium Chloride
dimethylphenylsilylmethylmagnesium chloride result in highly regioselective dehydrohalogenation. The reaction does not follow the conventional E2 elimination mechanism but includes beta-hydride elimination from the corresponding alkylcobalt intermediate. The interesting reaction mechanism of the cobalt-catalyzed dehydrohalogenation offered unique transformations that are otherwise difficult to attain.
One-Pot Stereoselective Synthesis of (<i>Z</i>)-1,2-Disubstituted Vinyl Sulfones by Hydrostannylation–Stille Tandem Reaction of Acetylenic Sulfones
作者:Guiqin Chen、Yan Yu、Mingzhong Cai
DOI:10.1080/00397910802531971
日期:2009.3.25
Abstract (Z)-1,2-Disubstituted vinyl sulfones can be stereoselectively synthesized in one pot under mild conditions, in good yields, by the palladium-catalyzed hydrostannylation of acetylenic sulfones with tributyltin hydride, followed by Stille coupling with aryl iodides.
A One-Pot, Stereoselective Synthesis of (<i>Z</i>)-1,2-disubstituted Vinyl Sulfides by Sequential Hydrostannylation and Stille reaction of Acetylenic Sulfides with Tributyltin Hydride and then with aryl iodides
作者:Wenyan Hao、Dong Wang、Mingzhong Cai
DOI:10.3184/030823407x228777
日期:2007.7
( Z)-1,2-Disubstituted vinyl sulfides can be stereoselectively synthesised in one pot under mild conditions, in good yields, by the palladium-catalysed hydrostannylation of acetylenic sulfides, followed by Stille coupling with aryl iodides.
作者:Radim Hrdina、Christian E. Müller、Raffael C. Wende、Katharina M. Lippert、Mario Benassi、Bernhard Spengler、Peter R. Schreiner
DOI:10.1021/ja110685k
日期:2011.5.25
We present a new class of catalysts based on the combination of N,N'-diaryl(thio)ureas and weak silicon Lewis acids (e.g., SiCl(4)). Such silicon-(thio)urea catalysts effectively catalyze the stereospecific rearrangement of epoxides to quaternary carbaldehydes.