Palladium-Catalyzed Cross-Coupling Reaction of Bis(pinacolato)diboron with 1-Alkenyl Halides or Triflates: Convenient Synthesis of Unsymmetrical 1,3-Dienes via the Borylation-Coupling Sequence
1-alkenylboronic acid pinacol esters via a palladium-catalyzed cross-coupling reaction of bis(pinacolato)diboron (pin(2)B(2), pin = Me(4)C(2)O(2)) with 1-alkenyl halides or triflates was carried out in toluene at 50 degrees C in the presence of KOPh (1.5 equiv) and PdCl(2)(PPh(3))(2)-2Ph(3)P (3 mol %). The borylation of acyclic and cyclic 1-alkenyl bromides and triflates was achieved in high yields with complete
Addition and Coupling Reactions of Bis(pinacolato)diboron Mediated by CuCl in the Presence of Potassium Acetate
作者:Kou Takahashi、Tatsuo Ishiyama、Norio Miyaura
DOI:10.1246/cl.2000.982
日期:2000.9
The addition of bis(pinacolato)diboron [(Me4C2O2)B-B(O2C2Me4)] to α,β-unsaturated ketones, esters, nitriles, or terminal alkynes and the coupling with allyl chlorides were carried out in DMF at room temperature in the presence of CuCl and AcOK. The transmetalation from boron to copper generating a B–Cu species was proposed as the key step of the reactions.
Atroposelective Synthesis of Conjugated Diene-Based Axially Chiral Styrenes via Pd(II)-Catalyzed Thioether-Directed Alkenyl C–H Olefination
作者:Liang Jin、Peng Zhang、Ya Li、Xin Yu、Bing-Feng Shi
DOI:10.1021/jacs.1c06236
日期:2021.8.11
The efficient stereoselective synthesis of conjugated dienes, especially those with axial chirality, remains a great challenge. Herein, we report the highly atroposelective synthesis of axially chiral styrenes with a conjugated 1,3-diene scaffold via a Pd(II)-catalyzed thioether-directed alkenyl C–H olefination strategy. This strategy features easy operation, mild reaction conditions, high functional
Synthesis of 1-Alkenylboronic Esters<i>via</i>Palladium-Catalyzed Cross-Coupling Reaction of Bis(pinacolato)diboron with 1-Alkenyl Halides and Triflates
The synthesis of 1-alkenylboronic acid pinacol esters via the palladium-catalyzed cross-coupling reaction of 1-alkenyl halides or triflates with bis(pinacolato)diboron [(Me4C2O2)B-B(O2C2 Me4)] was carried out in toluene at 50 °C in the presence of potassium phenoxide (1.5 equivalents) and PdCl2(PPh3)2·2PPh3 (3 mol%).
Copper(<scp>ii</scp>)-catalyzed protoboration of allenes in aqueous media and open air
作者:Russell F. Snead、Jan Nekvinda、Webster L. Santos
DOI:10.1039/d0nj02010a
日期:——
A method has been developed for the facile Cu(II)-catalyzed protoboration of monosubstituted allenes in aqueous media under atmospheric conditions. The reaction occurs site selectively, favoring internal alkene protoboration to afford 1,1-disubstituted vinylboronic acid derivatives (up to 93 : 7) with modest to good yields. The method has been applied to a variety of phenylallene derivatives as well