Direct Synthesis of Alkenylboronates from Alkenes and Pinacol Diboron via Copper Catalysis
作者:Wenkui Lu、Zengming Shen
DOI:10.1021/acs.orglett.8b03599
日期:2019.1.4
We report an efficient approach for the direct synthesis of alkenylboronates using copper catalysis. The Cu/TEMPO catalyst system (where TEMPO = (2,2,6,6-tetramethylpiperidin-1-yl)oxyl) exhibits both excellent reactivity and selectivity for the synthesis of alkenylboronates, starting from inexpensive and abundant alkenes and pinacol diboron. This approach allows for the direct functionalization of
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.
Synthesis of <i>Z</i>-(Pinacolato)allylboron and <i>Z</i>-(Pinacolato)alkenylboron Compounds through Stereoselective Catalytic Cross-Metathesis
作者:Elizabeth T. Kiesewetter、Robert V. O’Brien、Elsie C. Yu、Simon J. Meek、Richard R. Schrock、Amir H. Hoveyda
DOI:10.1021/ja403188t
日期:2013.4.24
first examples of catalytic cross-metathesis (CM) reactions that furnish Z-(pinacolato)allylboron and Z-(pinacolato)alkenylboron compounds are disclosed. Products are generated with high Z selectivity by the use of a W-based monoaryloxide pyrrolide (MAP) complex (up to 91% yield and >98:2 Z:E). The more sterically demanding Z-alkenylboron species are obtained in the presence of Mo-based MAP complexes
公开了提供Z-(频哪醇)烯基硼和Z-(频哪醇)烯基硼化合物的催化交叉复分解(CM)反应的第一实例。通过使用 W 基单芳氧基吡咯 (MAP) 络合物,生成具有高 Z 选择性的产品(产率高达 91%,Z:E >98:2)。在 Mo 基 MAP 配合物存在下,可以获得空间要求更高的 Z-烯基硼物质,产率高达 93%,Z 选择性高达 97%。首次报道了 1,3-二烯和芳基烯烃的 Z 选择性 CM。该方法与催化交叉偶联相结合的实用性通过抗癌剂考布他汀 A-4 的简洁和立体选择性合成得到了证明。