60835-95-2Relevant academic research and scientific papers
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.
THE PALLADIUM-CATALYSED CROSS-COUPLING REACTION OF 1-ALKENYLBORANES WITH ALLYLIC OR BENZYLIC BROMIDES. CONVENIENT SYNTHESIS OF 1,4-ALKADIENES AND ALLYLBENZENES FROM ALKYNES VIA HYDROBORATION
Miyaura, Norio,Yano, Takashi,Suzuki, Akira
, p. 2865 - 2868 (2007/10/02)
The reaction of allylic or benzylic bromides with 1-alkenyldisiamylboranes readily available from 1-alkynes in the presence of sodium hydroxyde and catalytic amounts of tetrakis-(triphenylphosphine)palladium to give corresponding 1,4-alkadienes or allylbe
