73062-33-6Relevant academic research and scientific papers
Oxime palladacycle-catalyzed Suzuki-Miyaura alkenylation of aryl, heteroaryl, benzyl, and allyl chlorides under microwave irradiation conditions
Civicos, Jose F.,Alonso, Diego A.,Najera, Carmen
supporting information; experimental part, p. 1683 - 1687 (2011/09/19)
A simple new protocol for the palladium-catalyzed Suzuki-Miyaura cross-coupling of organic chlorides under microwave irradiation is presented. Deactivated aryl and heteroaryl chlorides are efficiently cross-coupled with alkenylboronic acids and potassium alkenyltrifluoroborates using the 4,4′-dichlorobenzophenone oxime-derived palladacycle 1b as precatalyst in 0.1 to 0.5 mol% palladium loading, tris(tert-butyl)phosphonium tetrafluoroborate {[HP(t-Bu)3]BF4} as ligand, tetra-n-butylammonium hydroxide as cocatalyst, and potassium carbonate as base in N,N- dimethylformamide at 130°C under microwave irradiation conditions. Under these conditions, styrenes, stilbenes, and alkenylarenes are obtained in good to high yields, and with high regio- and diastereoselectivities in only 20 min. The reported protocol is also very efficient for the regioselective alkenylation of benzyl and allyl chlorides to afford allylarenes and 1,4-dienes. Copyright
Stereoselective synthesis of 1,4-dienylsilanes via hydromagnesiation of alkynylsilanes
Zhao, Hong,Hao, Wenyan,Cai, Mingzhong,Zhou, Zhou
, p. 780 - 781 (2007/10/03)
Hydromagnesiation of alkynylsilanes 1 gave (Z)-α-silylvinyl Grignard reagents 2, which underwent coupling reaction with allylic chlorides 3 to give stereoselectively 1,4-dienylsilanes 4 in good yields: the products 4 can undergo the desilylation reaction
Alkylation of Allylic Derivatives. 17. Cross-Coupling Reactions of Diallylic Pivalates with Butyl- and Phenylcopper Reagents
Underiner, Ted L.,Goering, Harlan L.
, p. 2563 - 2572 (2007/10/02)
Cross coupling (Z)-1-phenyl-1,4-pentadien-3-yl pivalate (cis-1-OPiv) with LiCuBu2, LiCu(CN)Bu, LiCuPh2 and LiCu(CN)Ph gives only the fully conjugated γ-coupling product.With LiCuBr2 substantial loss of double-bond configuration occures to give primarily the all-trans coupling product.With other cuprates, no detectable loss of double-bond configuration was observed.Cross coupling (Z)-3-(2-phenylethenyl)-2-cyclohexen-yl pivalate (cis-18-OPiv) with LiCuBu2, LiCuPh2, and LiCu(CN)Ph gives only α coupling product; with LiCu(CN)Bu, a mixture of α, γ, and ε coupling product was obtained.Cross coupling with LiCuBu2 results in loss of double-bond configuration in the α-alkylation product.With other cuprates, no loss of double-bond configuratiuon was detected in the α and γ coupling product.These results have profound mechanistic implications, which are discussed.The relationship between structure and reactivity was also investigated.A variety of diallylic pivalates (1-5-OPiv) were prepared and cross coupled with LiCuBu2, LiCu(CN)Bu, LiCuPh2, and LiCu(CN)Ph.Generally, coupling occurs at the least-substituted allylic system; mechanistic implications are discussed.
Novel and Convenient Method for the Stereo- and Regiospecific Synthesis of Conjugated Alkadienes and Alkenynes via the Palladium-Catalyzed Cross-Coupling Reaction of 1-Alkenylboranes with Bromoalkenes and Bromoalkynes
Miyaura, Norio,Yamada, Kinji,Suginome, Hiroshi,Suzuki, Akira
, p. 972 - 980 (2007/10/02)
Details of a new and general method for the stereo- and regiospecific synthesis of conjugated alkadienes and alkenynes are described.The reaction of (E)- or (Z)-1-alkenyldisiamylboranes, or 2-((E)-1-alkenyl)-1,3,2-benzodioxaboroles readily obtainable by hydroboration, with either (E)- or (Z)-1-alkenyl bromides in the presence of a catalytic amount of tetrakis(triphenylphosphine)palladium and bases such as sodium alkoxides gives the corresponding (E,E)-, (E,Z)-, (Z,E)-,or (Z,Z)-conjugated alkadienes stereo- and regiospecifically, while retaining the configurations of both the strating alkenylboranes and bromoalkenes.The reaction of (E)- and (Z)-1-alkenyldisiamylboranes with 1-bromoalkynes similarly provides a stereo- and regiospecific synthesis of conjugated (E)- and (Z)-alkenynes.A mechanism of this cross-coupling reaction, which involves the transmetalation between a 1-alkenylborane and an alkoxypalladium(II) complex generated through the metathetical displacement of a halogen atom from R(Pd(II)X with sodium alkoxide, is proposed.
