Palladium-Assisted Formation of Carbon-Carbon Bonds. 3. Study of Reactions of Bis{.eta.2-(2,3,4-trimethoxy-6- acetylphenyl-C,O)}di(.mu.-chloro)dipalladium(II) with Symmetrical and Unsymmetrical Internal Alkynes. A Stoichiometric Route to Highly Functionalized Spirocyclic and Benzofulvene Compounds. Isolation of a .pi.-Allylic Palladium Intermediate. X-ray Structure of 10-(1-Hydroxyethyl)-6,7-dimethoxy-1,2,3,4-tetraphenylspiro[4.5]1,3,6,9-decatetraen-8-one

1995 ◽  
Vol 14 (6) ◽  
pp. 2677-2688 ◽  
Author(s):  
Jose Vicente ◽  
Jose-Antonio Abad ◽  
Juan Gil-Rubio ◽  
Peter G. Jones
Keyword(s):  
X Ray ◽  
Carbon Carbon Bonds ◽  
Internal Alkynes ◽  
Carbon Bonds

Die oxidative Addition von NickeI(0)-KompIexen an Kohlenstoff-Kohlenstoff-Bindungen im Cyclobutadien. Zur Frage der Überführbarkeit von Cyclobutadien-Nickel(O)-Komplexen in Nickelaringe / Oxidative Addition of Nickel(O) Complexes to Carbon-Carbon Bonds in Cyclobutadiene. The Question of the Interconvertibility of Cyclobutadiene-nickel(O) Complexes and the Nickelaring Systems

1985 ◽  
Vol 40 (5) ◽  
pp. 624-635 ◽  
Author(s):  
John J. Eisch ◽  
Andrzej M. Piotrowski ◽  
Allen A. Aradi ◽  
Carl Krüger ◽  
Maria J. Romão
Keyword(s):  
Spectral Data ◽  
Structure Determination ◽  
Oxidative Addition ◽  
Subsequent Treatment ◽  
X Ray ◽  
X Ray Crystallography ◽  
Carbon Carbon Bonds ◽  
Elemental Analyses ◽  
Carbon Bonds

Abstract Bis(triethylphosphine)(η4-tetraphenylcyclobutadiene)nickel (4) was synthesized by the reduction of (η4-tetraphenylcyclobutadiene)nickel(II)bromide (3) with t-butyllithium in the presence of Et3P, and its structure was determined by X-ray crystallography. Furthermore, its reactivity towards CO, CH3CO2H, PhC≡CPh, LiAlH4 and O2 were investigated. 1,1-Bis(triethylphos-phine)-2,3,4,5-tetraphenylnickelole (14) was synthesized from (E,E)-1,4-dilithio-1,2,3,4-tetraphenyl-1,3-butadiene (15) and bis(triethylphosphine)nickel(II)bromide. Since the resulting crystals of the nickelole were not suitable for X-ray structure determination, the compound was characterized by elemental analyses, spectral data and carbonylation to yield tetraphenylcyclo-pentadienone (6).Analogous reductions of (η4 -tetraphenylcyclobutadiene)nickel(II)bromide (3) in the presence of Ph3P or Ph2PCH2CH2PPh2 , followed by carbonylation, led to 6 in 40% yield, demonstrating that about half of the cyclobutadiene rings in 3 undergo cleavage upon reduction to give the nickelole.Reactions of the dilithium reagent 15 with NiBr2 complexed with Me2PCH2CH2PMe2 ,Ph3P or Et2PCH2CH2PEt2 , led to the formation of thermolabile nickeloles, as demonstrated by carbonylàtion which yielded 6. Warming of the nickeloles and subsequent treatment with CH3CO2H led to the formation of 1,2,3,4,5,6,7,8-octaphenyl-1,3,5,7-octatetraene (8) and, in one case, octaphenyl-cyclooctatetraene (5).The relevance of these findings to the mechanism of the Reppe nickel-catalyzed oligomerization of alkynes is discussed.

Palladium-Assisted Formation of Carbon−Carbon Bonds. 8.1Synthesis and Reactivity toward Internal Alkynes, Carbon Monoxide, and Isocyanides of Orthopalladated Dibenzylamine Complexes

1999 ◽  
Vol 18 (14) ◽  
pp. 2683-2693 ◽  
Author(s):  
José Vicente ◽  
Isabel Saura-Llamas ◽  
Juana Turpín ◽  
M. Carmen Ramírez de Arellano ◽  
Peter G. Jones
Keyword(s):  
Carbon Monoxide ◽  
Carbon Carbon Bonds ◽  
Internal Alkynes ◽  
Carbon Bonds
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