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[
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[
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[
Activation of Terminal Alkynes by Frustrated Lewis Pairs
作者:Chunfang Jiang、Olivier Blacque、Heinz Berke
DOI:10.1021/om9008636
日期:2010.1.11
The reactions of frustratedLewispairs (FLPs) derived from B(C6F5)3 and the bulky Lewis bases 2,2,6,6-tetramethylpiperidine (TMP), tri-tert-butylphosphine, and lutidine (Lut) with terminalalkynes (acetylene, phenylacetylene, 3-ethynylthiophene) were investigated. The FLPs TMP···B(C6F5)3,t-Bu3P···B(C6F5)3 and Lut···(C6F5)3 reacted with acetylene (HC≡CH) to yield the apparently thermodynamically more
受挫路易斯双(FLP信号)为B(C导出的反应6 ˚F 5)3和笨重的路易斯碱-2,2,6,6-四甲基哌(TMP),三-叔丁基膦,和二甲基吡啶(甩)与终端研究了炔烃(乙炔,苯乙炔,3-乙炔基噻吩)。FLP TMP ···(C 6 F 5)3,t- Bu 3 P···B(C 6 F 5)3和Lut ···(C 6 F 5)3与乙炔(HC≡CH)反应生成明显热力学更稳定的E异构体[ TMP H] [(C 6 F 5)2 B-C(C 6 F 5)═C(H)B(C 6 F 5)3 ](1- E),t- Bu 3 PC(H)═C(H)B(C 6 F 5)3(2- E ; 90%)和[ t- Bu 3 PH] [(C 6 F 5)2 B-C(C 6 F 5)═C(H)B(C 6 F 5)3 ](3- E ; 10%)和Lut C(H)═C(H)B(C 6 F 5)3(4- E) 。乙炔反应的机械途径建议从形成弱的B(C
Exploring the Limits of Frustrated Lewis Pair Chemistry with Alkynes: Detection of a System that Favors 1,1-Carboboration over Cooperative 1,2-P/B-Addition
[(C6F5)2B‐(CH2)3‐Cp}(Cp‐PtBu2)ZrCl2] (6; Cp=cyclo‐C5H4) was prepared by hydroboration of [(allyl‐Cp)(Cp‐PtBu2)ZrCl2] (5) with HB(C6F5)2 (“Piers’ borane”). It represents a frustratedLewispair (FLP) in which both the Lewis acid and the Lewis base were attached at the metallocene framework. Its reaction with 1‐pentyne did not result in the 1,2‐addition of or deprotonation reaction by the FLP, but rather in
锆茂复合物[(C 6 F 5)2 B-(CH 2)3 -Cp}(Cp-P t Bu 2)ZrCl 2 ](6 ; Cp = cyclo-C 5 H 4)是通过对[(烯丙基-Cp)(Cp-P t Bu 2)ZrCl 2 ](5)与HB(C 6 F 5)2(“ Piers'borane”)。它代表沮丧的路易斯对(FLP),其中路易斯酸和路易斯碱都连接在茂金属骨架上。它与1-戊炔的反应不会导致FLP的1,2-加成或去质子反应,而是三键的1,1-碳环化,从而获得Z / E混合物(1.2:1)各自的有机金属取代的烯烃7。1-戊炔与无磷体系[(C 6 F 5)2 B-(CH 2)3 -Cp)} CpZrCl 2 [ 9 ]的类似反应给出了各自的1,1-碳化产物(Z ‐10/ E- 10≈1.3:1)。
Characterization of the Zwitterionic Intermediate in 1,1‐Carboboration of Alkynes
作者:Alessandro Bismuto、Gary S. Nichol、Fernanda Duarte、Michael J. Cowley、Stephen P. Thomas
DOI:10.1002/anie.202003468
日期:2020.7.27
intermediates generated by reaction of B(C6F5)3 with alkynes. The stepwise reactivity of the zwitterion provides new mechanistic insight for 1,1‐carboboration and wider B(C6F5)3 catalysis. Making use of intramolecular stabilization by a ferrocene substituent, we have characterized the zwitterionic intermediate in the solid state and diverted reactivity towards alkyne cyclotrimerization.
Lewis酸性硼烷与炔烃的反应是各种主基团转化过程中的关键步骤。Wrackmeyer反应是炔烃1,1-碳硼化反应,是这种原型转化。有人建议通过两性离子中间体进行1,1-碳硼化。我们报告了由B(C 6 F 5)3与炔烃反应生成的两性离子中间体的分离及光谱,结构和计算特征。两性离子的逐步反应性为1,1-碳硼化和更广泛的B(C 6 F 5)3提供了新的机理见解催化。利用二茂铁取代基的分子内稳定作用,我们表征了固态的两性离子中间体,并转移了对炔烃环三聚反应的反应性。
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[