1,1-Carboboration of 1-Alkynes: A Conceptual Alternative to the Hydroboration Reaction
摘要:
Strongly electrophilic boranes R-B(C6F5)(2) react readily with a variety of 1-alkynes by means of a 1,1-carboboration reaction to yield alkenylborane products, which can subsequently be used as reagents in metal catalyzed cross-coupling reactions.
1,1-Carboboration of 1-Alkynes: A Conceptual Alternative to the Hydroboration Reaction
摘要:
Strongly electrophilic boranes R-B(C6F5)(2) react readily with a variety of 1-alkynes by means of a 1,1-carboboration reaction to yield alkenylborane products, which can subsequently be used as reagents in metal catalyzed cross-coupling reactions.
通过1,1-碳链化路线制备了一系列烯基硼烷,并将其用作路易斯酸组分,用于产生沮丧的路易斯对(FLP)。1-炔烃与B(C 6 F 5)3的反应得到RCH═C(C 6 F 5)B(C 6 F 5)2系统4a(R = n -C 3 H 7),4b(R = n -C 4 H 9),4c(R = Ph)和4d(R = t -C 4 H 9), 分别。在环境温度下,衍生自化合物4a – d的烯基硼烷/ t Bu 3 P FLP与二氢(2.5 bar)迅速反应。笨重的系统4D离开alkenylborane不饱和的C = C双键和,得到二氢裂解产物[吨卜3 PH] [吨BuCH═C(C 6 ˚F 5)BH(C 6 ˚F 5)2 ](10D) 。相比之下,体积较小的系统4a / t, Bu 3 P和4b / t在这些条件下,Bu 3 P分解成二氢,并干净地还原了它们的C═C双键,生成了相应的1-五氟苯基烷基氢硼酸盐[
Stoichiometric and catalytic isomerization of alkenylboranes using bulky Lewis bases
作者:Fu An Tsao、Anson Sathaseevan、Hui Zhu、Stefan Grimme、Gerhard Erker、Douglas W. Stephan
DOI:10.1039/c7cc04904h
日期:——
isomers of RCH = CR′B(C6F5)2 (R = (CH2)2Me, (CH2)3Me, (CH2)2Ph, CH2CHMe2, CHMe2, CMe3, CH2OMe, CH2N(CO)2C6H4), treatment of these alkenylboranes with stoichiometric or catalytic amounts of tBu2PH or other donors are shown to induce isomerization. The proposed mechanism involving a zwitterionic borataalkene intermediate is supported by computations.
与硼烷R'B炔烃的1,1- Carboboration(C 6 ˚F 5)2(R'=(CH 2)3博士,C 6 ˚F 5)所述的,得到的混合物Ë和Ž RCH = CR'B的异构体( C 6 F 5)2(R =(CH 2)2 Me,(CH 2)3 Me,(CH 2)2 Ph,CH 2 CHMe 2,CHMe 2,CMe 3,CH 2 OMe,CH 2 N(CO) )在2 C 6 H 4)中,显示出用化学计量或催化量的t Bu 2 PH或其他供体处理这些烯基硼烷会诱导异构化。计算结果支持了所提出的涉及两性离子硼烷基烯烃中间体的机理。
1,1-Carboboration of 1-Alkynes: A Conceptual Alternative to the Hydroboration Reaction
Strongly electrophilic boranes R-B(C6F5)(2) react readily with a variety of 1-alkynes by means of a 1,1-carboboration reaction to yield alkenylborane products, which can subsequently be used as reagents in metal catalyzed cross-coupling reactions.
Alkenylborane-Derived Frustrated Lewis Pairs: Metal-Free Catalytic Hydrogenation Reactions of Electron-Deficient Alkenes
作者:J. Sreedhar Reddy、Bao-Hua Xu、Tayseer Mahdi、Roland Fröhlich、Gerald Kehr、Douglas W. Stephan、Gerhard Erker
DOI:10.1021/om3006068
日期:2012.8.13
these alkenylboranes undergo FLP reactions acting as catalysts for the hydrogenation of imines. Perhaps most remarkably, some of these alkenylboranes retain the C═C double bonds under FLP/H2 reaction conditions and heterolytically split dihydrogen in the presence of the Lewis base DABCO and catalyze the hydrogenation of the electron-poor C═C double bonds of diaryl-substituted enones.
通过1,1-碳链化路线制备了一系列烯基硼烷,并将其用作路易斯酸组分,用于产生沮丧的路易斯对(FLP)。1-炔烃与B(C 6 F 5)3的反应得到RCH═C(C 6 F 5)B(C 6 F 5)2系统4a(R = n -C 3 H 7),4b(R = n -C 4 H 9),4c(R = Ph)和4d(R = t -C 4 H 9), 分别。在环境温度下,衍生自化合物4a – d的烯基硼烷/ t Bu 3 P FLP与二氢(2.5 bar)迅速反应。笨重的系统4D离开alkenylborane不饱和的C = C双键和,得到二氢裂解产物[吨卜3 PH] [吨BuCH═C(C 6 ˚F 5)BH(C 6 ˚F 5)2 ](10D) 。相比之下,体积较小的系统4a / t, Bu 3 P和4b / t在这些条件下,Bu 3 P分解成二氢,并干净地还原了它们的C═C双键,生成了相应的1-五氟苯基烷基氢硼酸盐[