Halodeboronation of organotrifluoroborates using tetrabutylammonium tribromide or cesium triiodide
作者:Min-Liang Yao、George W. Kabalka、David W. Blevins、Marepally Srinivasa Reddy、Li Yong
DOI:10.1016/j.tet.2012.03.016
日期:2012.5
Halodeboronation of organotrifluoroborates using commercially available tetrabutylammoniumtribromide (TBATB) or cesium triiodide in aqueous medium is reported. The mild, transition metal-free method has proven to be tolerant of a wide range of functional groups. High regio- and chemoselectivity are observed. Two synthetic routes to (Z)-dibromoalkenes from alkynes, through stereodefined (Z)-2-brom
Base-catalyzed diborylation of alkynes: synthesis and applications of cis-1,2-bis(boryl)alkenes
作者:Zhijie Kuang、Guoliang Gao、Qiuling Song
DOI:10.1007/s11426-018-9344-4
日期:2019.1
An efficient, transition-metal free, and practical approach to cis-bis(boryl)alkenes from various alkynes was disclosed in the presence of a catalytic amount of K2CO3 under mild conditions. Meanwhile, tetrasubstituted alkenes and phenanthrene derivatives were readily constructed from the target diborylalkenes via Suzuki-Miyaura cross coupling.
公开了在温和条件下在催化量的K 2 CO 3存在下从各种炔烃制得的有效,无过渡金属且实用的方法来从各种炔烃中制备顺式-双(硼基)烯烃。同时,通过铃木-宫浦(Suzuki-Miyaura)交叉偶合容易地由目标二硼烷基烯烃构建四取代的烯烃和菲衍生物。
Gold-Nanoparticle-Catalyzed Mild Diboration and Indirect Silaboration of Alkynes without the Use of Silylboranes
作者:Marios Kidonakis、Manolis Stratakis
DOI:10.1002/ejoc.201700754
日期:2017.8.10
take place and the in situ formation of the Au nanoparticle-tethered silylborane. Given that the Au-catalyzed silaboration of alkynes is faster than the rates of the corresponding disilylation and diboration pathways, we were able to achieve the indirect silaboration of alkynes with good chemoselectivities (65–85 %) without the direct use of silylboranes, which are expensive and difficult to synthesize
负载在TiO 2上的可商购的Au纳米颗粒被用于催化双(频哪醇)二硼烷末端和内部炔烃的顺式硼化反应。通过使用温和的条件,更短的反应时间和比非均相Au纳米孔催化剂所需的催化剂负载低的催化剂负载量,可以以优异的产率获得产物。可以将催化系统回收并重复使用五次,而不会损失任何活性。在Au / TiO 2存在下双(频哪醇)二硼与1,2-二硅烷的组合允许σ键复分解发生并原位形成Au纳米粒子束缚的甲硅烷基硼烷。鉴于Au催化炔烃的硅烷化比相应的二甲苯化和硼氢化途径的速率快,我们能够在不直接使用甲硅烷基硼烷的情况下实现具有良好化学选择性(65-85%)的炔烃的间接硅烷化。昂贵且难以合成。
Mixed Diboration of Alkynes Catalyzed by LiOH: Regio- and Stereoselective Synthesis of <i>cis-</i>1,2-Diborylalkenes
作者:Sihan Peng、Guixia Liu、Zheng Huang
DOI:10.1021/acs.orglett.8b02830
日期:2018.12.7
A diboration of terminal alkynes with an unsymmetrical diboron reagent pinBBdan has been achieved using LiOH as the catalyst in the presence of stoichiometric amounts of MeOH, affording 1,2-diborylalkenes with different boryl groups. The reaction proceeds in a highly regio- and stereoselective manner through cis-addition of pinBBdan to the C–C triple bond, with the Bdan moiety being incorporated at
alkynes and alkenes undersolvent‐ and ligand‐freeconditions in air. The cis‐1,2‐diborylalkenes and 1,2‐diborylalkanes were obtained in moderate to excellent yields following, in most cases, a simple filtration workup protocol. The versatility of the cis‐1,2‐diboronvinyl compounds was demonstrated in a series of organic transformations, including the Suzuki–Miyauracrosscoupling and the boron–halogen