Isolement «chromatographique» a la surface d'un film poreux depolymere, et analysis des intermediaires par ESCA。例如:decarbonylation de chlorures d'acides par un catalyseur de Wilkinson
The<i>in situ</i>-Generated Nickel(0)-catalyzed Homo-coupling of Alkenyl Halides with Zinc Powder. A Specific Outcome in Stereochemistry
作者:Kentaro Takagi、Harutaka Mimura、Saburo Inokawa
DOI:10.1246/bcsj.57.3517
日期:1984.12
The catalytic activity of nickel(0) generated in situ from nickel(II) salt was examined in a dehalogenative coupling of alkenylhalides with zinc powder. The reaction of alkenyl bromides took place provided that potassium iodide was present to assist the reduction of nickel(II) with zinc powder, and also to convert the alkenyl bromides to the corresponding alkenyl iodides. A speculative view concerning
在烯基卤化物与锌粉的脱卤偶联中检测了从镍 (II) 盐原位生成的镍 (0) 的催化活性。烯基溴化物的反应发生,前提是存在碘化钾以帮助用锌粉还原镍 (II),并将烯基溴化物转化为相应的烯基碘化物。为了解释观察到的独特立体化学,提出了关于歧化步骤的推测性观点。
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
Electrochemical carboxylation of alkyl-substituted vinyl bromides (1a-1g) in the presence of 20 mol% of NiBr2•bpy under an atmospheric pressure of carbon dioxide with a platinum cathode and a magnesium anode gave the corresponding α,β-unsaturated carboxylic acids (2a-2g) in yields of 53-82%.
Comparison of syn dehydrohalogenations from -1-bromo-2-chlorocycloalkanes promoted by complex base and by potassium -butoxide
作者:Alan P. Croft、Richard A. Bartsch
DOI:10.1016/s0040-4039(00)88009-0
日期:1983.1
Compared with t-BuOK-t-BuOH, syn eliminations from trans-1-bromo-2-chlorocycloalkanes (C4-C8) induced by NaNH2-NaO-t-Bu in THF are rapid, exhibit greater propensity for dehydrechlorination and show little sensitivity to ring size of the dihalocycloalkane.
NICKEL-CATALYZED ULLMANN-TYPE COUPLING OF ALKENYL HALIDES WITH ZINC POWDER
作者:Kentaro Takagi、Naomi Hayama
DOI:10.1246/cl.1983.637
日期:1983.5.5
Convenient procedure for an Ullmann-type coupling of alkenyl halides using zinc powder, nickel(II) chloride, and potassium iodide and/or thiourea is presented. One double bond in the produced diene retained the configuration of a starting material, while partial cis–trans isomerization was observed in the second one.