- Allenylpalladium(II) Species: Possible Intermediates in the Tetrakis(triphenylphosphine)palladium(0)-catalysed Formation of Allenes from Prop-2-ynylic Substrates
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The formation of a 3-methylbuta-1,2-dienylpalladium(II) complex (2) from the prop-2-ynylic chloride (1a) or the prop-2-ynylic acetate (1b) and tetrakis(triphenylphosphine)palladium(0), as well as its conversion into the allenes (4), is described.
- Elsevier, Cornelis J.,Kleijn, Henk,Ruitenberg, Klaas,Vermeer, Peter
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p. 1529 - 1530
(2007/10/02)
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- Organometal-mediated synthesis of conjugated allenynes, allenediynes, vinylallenes and diallenes
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An extensive study of the reactivity of organometallic reagents R3M (R3 = 1-alkenyl, 1-alkynyl, 3-alken-1-ynyl, 1,3-alkadiynyl or 1,2-alkadienyl; M = Li, MgCl, ZnCl, Cu, Ag) towards R1R2C=C=CH-X (1) and R1R2C(X)-CCH (4) is described.High yields of R1R2C=C=CH=R3 (2) have been obtained by reaction of 1 (X = Br) with R3-M (M = MgCl, ZnCl or Cu1/2Li1/2) using Pd4 as catalyst.Similarly, pure 2 have been obtained by the Pd4-catalyzed reaction of 4 (X = Br, OAc, OS(O)Me, OSO2Me, OP(O)(OEt)2) with R3-M (M = MgCl, ZnCl, Zn1/2, Cu, Cu1/2Li1/2, Ag or Ag1/2Li1/2).In some reactions with R3-Cu, compounds 4 were cnverted into 2 in the absence of the palladium catalyst.
- Ruitenberg, K.,Kleijn, H.,Westmijze, H.,Meijer, J.,Vermeer, P.
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p. 405 - 409
(2007/10/02)
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- PALLADIUM(0)-PROMOTED SYNTHESIS OF FUNCTIONALLY SUBSTITUTED ALLENES BY MEANS OF ORGANOZINC COMPOUNDS
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The paper describes new routes to aryl-, vinyl-, and 1-alkynylallenes and to diallenes via Pd(PPh3)4-promoted reaction of propargylic or allenic halides with appropriate organozinc halides.Propargylic acetates are also suited to prepare such allenes.
- Ruitenberg, K.,Kleijn, H.,Elsevier, C. J.,Meijer, J.,Vermeer, P.
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p. 1451 - 1452
(2007/10/02)
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