109432-91-9Relevant academic research and scientific papers
Heck Reactions Starting from Silyl Enol Ethers - A Simple One-Pot Nonaflation-Coupling Procedure for the Synthesis of 1,3-Dienes
Webel, Matthias,Reissig, Hans-Ulrich
, p. 1141 - 1142 (1997)
Starting from silyl enol ether 4 the corresponding alkenylnonaflate 5 was generated by treatment with nonafluorobutanesulfonyl fluoride (NfF) and a catalytic amount of tetra-n-butylammonium fluoride (TBAF). By Pd-catalysis 5 was directly Heck-coupled with
Synthesis of 1,3-Dienes via a Sequential Suzuki-Miyaura Coupling/Palladium-Mediated Allene Isomerization Sequence
Al-Jawaheri, Yassir,Kimber, Marc C.
supporting information, p. 3502 - 3505 (2016/07/23)
We report a facile method for the synthesis of 1,3-dienes by a sequential process consisting of a palladium-catalyzed, base-free, Suzuki-Miyaura coupling/isomerization sequence. This sequence couples boronic acids with propargyl alcohols, generating the requisite allene in situ, followed by conversion of the unactivated allene to its 1,3-diene via a hydro-palladation/dehydro-palladation process. This process is general for a range of boronic acids, including boronic acids with electron-donating and -withdrawing groups, as well as heteroarylboronic acids. Key to this process is the boric acid byproduct of the base-free Suzuki-Miyauru coupling, which generates the required palladium-hydrido complex [H-PdII-OB(OH)2] required for the isomerization.
Heck reaction of vinyl bromides with alkenes in the presence of a tetraphosphine/palladium catalyst
Berthiol, Florian,Doucet, Henri,Santelli, Maurice
, p. 841 - 844 (2007/10/03)
Through the use of [PdCl(C3H5)]2- cis,cis,cis-1,2,3,4-tetrakis(diphenylphosphinomethyl)cyclopentane as a catalyst, a range of vinyl bromides undergo Heck reaction with a wide variety of alkenes leading selectively to the corresponding 1,3-dienes in good yields. Furthermore, it can be used at low loading even for reactions of sterically hindered vinyl bromides.
One-pot transformation of silyl enol ethers into 1,3-dienes: In situ generation of alkenyl nonaflates and subsequent Heck reactions - Scope and limitations
Lyapkalo, Ilya M.,Webel, Matthias,Reissig, Hans-Ulrich
, p. 3646 - 3658 (2007/10/03)
Palladium-catalysed reactions between methyl acrylate and the isolated alkenyl nonaflates 2a, 2d and 2e proceed without difficulties, furnishing the desired 1,3-dienes 3, 14 and 15 in good yields. The use of other alkenyl nonaflates and olefins in this Heck reaction was also examined. The main purpose of this study was the development of an in situ generation of the required alkenyl nonaflates 2 from the corresponding silyl enol ethers 1 and their one-pot transformation into 1,3-dienes. Thus, the previously described fluoride-promoted exchange of the trimethylsilyl substituent of typical enol ethers 1 for a nonafluorobutylsulfonyl group was directly combined with the palladium-catalysed coupling step. This sequence allowed the efficient transformation of a variety of silyl enol ethers 1 into highly substituted 1,3-dienes in a practical one-pot procedure. The scope and limitations, together with the chemo- and stereoselectivity, of this process are discussed. A particular intriguing example involves a one-pot synthesis of silyl enol ether 1j by means of a Diels-Alder reaction, subsequent nonaflation and a Heck reaction with tert-butyl acrylate, furnishing the highly functionalised 1,3-diene 30 in good overall yield. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.
