Diethyldipyridylnickel. Preparation, Characterization, and Reactions

Palladium‐Catalyzed Cross‐Coupling: A Historical Contextual Perspective to the 2010 Nobel Prize

“…[61] By 1966, formation of butane from the thermal decomposition of [Et 2 Ni(byp)] (byp = 2,2'bipyridine) had been observed by Yamamoto. [62] Furthermore, in 1970, Yamamoto isolated and characterized the first nickel-aryl chloride oxidative addition product. [63] In 1971, Semmelhack would take advantage of these earlier reports, and disclosed the homodimerization of aryl halides using stoichiometric quantities of [Ni(cod) 2 ] (cod = 1,5-cyclooctadiene).…”

Stabilities of nickel–alkyl compounds

“…Normally the methyl triplet is at higher field than the methylene quartet, but there have been several reports (3,15) of spectra of ethyl metal compounds in which the methvlene resonance is at a similar or even higher field than the methyl resonance, presumably because of the low electronegativity of the metal. The spectrum of the ethyl compound, K-C5H5Ni(PPh3)Et, is very similar to the spectra of several ethyl silicon and zinc compounds (15), and thus the K-C,H,Ni(PPh,) group appears to have a rather low electronegativity.…”

“…studies, we have investigated the properties of Similar products have been reported from the the homologous series n-C5H5Ni(PPh,)R, where thermal decomposition of n-butyl(tri-n-butyl-R = methyl, ethyl, n-propyl, iso-propyl, n-butyl, phosphine)copper(I) (2), diethyl (cl,clf-dipyrida1)-sec-butyl, iso-butyl and tert-butyl. This series is nickel(I1) (3), and diethylbis(cl,af-dipyrida1)-apparently unique, in that it appears to be the iron(I1) (4), while reactions of Grignard reagents only one known in which the higher branched with transition metal halides have long been chain derivatives are stable enough to be isolated known (5) to yield olefins and alkanes, presum-and characterized; even platinum sec-and isoably from the decomposition of unstable alkyl-compounds are unknown, although the normal metal derivatives. Some compounds of platinum alkyl derivatives are extremely stable (9).…”

Palladiumkatalysierte Kreuzkupplungen: eine historische Perspektive im Kontext der Nobel‐Preise 2010

“…Ich entschied mich zu prüfen, was passiert, wenn eine Organopalladiumverbindung ohne b-Wasserstoffatome in Gegenwart von etwas anderem hergestellt wird … Im ersten Experiment gab ich Phenylquecksilberacetat zu einer Lçsung von Lithiumtetrachloropalladat in Acetonitril, die bei 0 8C unter Ethenatmosphäre gerührt wurde. [62] Yamamoto isolierte und charakterisierte 1970 auch das erste Produkt der oxidativen Addition eines Arylchlorids an Nickel. [51] Diese Beobachtung zog im Jahr 1968 die Verçffentlichung einer Reihe von sieben Zuschriften nach sich, in denen Heck als einziger Autor die Reaktionen von Organoquecksilberverbindungen mit Olefinen in Gegenwart katalytischer Mengen von Li 2 [PdCl 4 ] beschrieb (Schema 11).…”

“…[57] Überdies hat die Fähigkeit zur Einführung quartärer Stereozentren durch intramolekulare Prozesse, [58] in Kombination mit der Entwicklung asymmetrischer Versionen, [59] [61] und 1966 beobachtete A. Yamamoto die Bildung von Butan bei der thermischen Zersetzung von [Et 2 Ni(byp)] (byp = 2,2'-Bipyridin). [62] Yamamoto isolierte und charakterisierte 1970 auch das erste Produkt der oxidativen Addition eines Arylchlorids an Nickel. [63] 1971 gelang Semmelhack, aufbauend auf diesen früheren Berichten, die Homodimerisierung eines Arylhalogenids durch den Einsatz stçchiometrischer Mengen an [Ni-(cod) 2 ] (cod = 1,5-Cyclooctadien).…”