128708-74-7Relevant academic research and scientific papers
ortho-Chelating Arenethiolatocopper(I) Complexes as Versatile Catalysts in the Regioselective Cross-Coupling of Allylic Derivatives with nBuMgI - An Example of Reversed Reactivity of Leaving Groups
Persson, Eva S. M.,Klaveren, Mayra van,Grove, David M.,Baeckvall, Jan E.,Koten, Gerard van
, p. 351 - 359 (2007/10/03)
The regioselectivity in the arenethiolactocopper(I)-catalyzed cross-coupling reaction of allylic substrates was studied.It was found that allylic acetates gave highly γ-selective reactions in Et2O at 0 deg C with slow addition of the Grignard reagent, whereas α-selective reactions were obtained in THF at -30 deg C with fast addition of the Grignard reagent.It is proposed that the formation of an intermediate in Et2O, in which the allylic acetate coordinates in a bidentate fashion to the arenethiolatocopper(I) catalyst, dramatically increases the reactivity of the leaving group and results in excellent γ-selectivity.The remarkable observation that an allylic acetate can be made more reactive than an allylic chloride by using the arenethiolatocopper(I) catalyst 1a supports the theory of a bidentate coordination of the substrate to the catalyst through its double bond and acetate oxygen. - Keywords: allylic substrates . carbon-carbon coupling . catalysis . copper compounds
The use of metal reagents in stereo- and regioselective functionalizations of conjugated dienes
Baeckval, Jan-E
, p. 665 - 670 (2007/10/02)
Conjugated dienes have been selectively functionalized via 1-acetoxy-4-chloro-2-alkenes and via 2-(phenylsulfonyl)-1,3-dienes.In both these approaches nucleophiles can be added to the 1- and 4-positions.It was shown that also non-stabilized carbon nucleophiles (from cuprates or copper(I)-catalyzed Grignard reactions) can be used.The utility of the functionalizations was demonstrated by the syntheses of a marine natural product and a butterfly pheromone.Finally, the 2-(phenyl-sulfonyl)-1,3-dienes show a dual electron demand in Diels-Alder reactions and give cycloadducts with both electron-rich and electron-deficient olefins.
