(1R,2R)-1-((E)-Styryl)-2-methylcyclopropane 在 250 o C 外消旋并异构化为 6-苯基六-1,4-(Z)-二烯和 3-苯基-的四种异构体4-甲基环戊烯。从外消旋化和结构异构化的测量速率常数,以及四种 3-苯基-4-甲基环戊烯的相对量随时间变化的信息,四种立体化学不同路径对这种乙烯基环丙烷重排的相对贡献是发现为 60% si、10% ar、19% sr 和 11% ai
Nickel-Catalyzed Reductive Deoxygenation of Diverse C–O Bond-Bearing Functional Groups
作者:Adam Cook、Haydn MacLean、Piers St. Onge、Stephen G. Newman
DOI:10.1021/acscatal.1c03980
日期:2021.11.5
We report a catalytic method for the direct deoxygenation of various C–O bond-containing functional groups. Using a Ni(II) pre-catalyst and silane reducing agent, alcohols, epoxides, and ethers are reduced to the corresponding alkane. Unsaturated species including aldehydes and ketones are also deoxygenated via initial formation of an intermediate silylated alcohol. The reaction is chemoselective for
Synthesis of organolithium compounds from phenyl selenides
作者:Alain Krief、Abdesslame Nazih、Myriam Hobe
DOI:10.1016/0040-4039(95)01689-f
日期:1995.10
Alkyl aryl selenides react with lithium arenides to produce, regioselectively, alkyllithiums and lithium arylselenolates. Experimental conditions, especially the temperature, have a profound effect on the course of this reaction and on the nature of the products.
Arylcycloalkanes have been prepared from acetophenone by a three-step sequence involving the synthesis of α-pheny(ω-alkenyl)methylselenides and their reaction with butyl-lithium reagents to give an intermediate which adds across the CC double bond to give 2-methyl-2-phenylcycloalkylmethyl-lithiums with stereocontrol; other syntheses of these compounds are also described.
Diastereoselective Hydrogenation of Tetrasubstituted Olefins using a Heterogeneous Pt‐Ni Alloy Catalyst
作者:William A. Swann、Anish Yadav、Nicholas B. Colvin、Nicole K. Freundl、Christina W. Li
DOI:10.1002/anie.202317710
日期:2024.5.6
A Pt−Ni alloy nanocatalyst is developed for the diastereoselective directed hydrogenation of tetrasubstituted olefins in a cyclopentene scaffold. For this substrate class, established homogeneous catalysts generate hydrogenolysis side products, and commercial heterogeneous catalysts are not stereoselective. Uniform alloying of the noble metal and base metal combined with high catalyst dispersion is