作者:Nirmalya Mukherjee、Debasish Kundu、Brindaban C. Ranu
DOI:10.1002/adsc.201600933
日期:2017.1.19
develop a decyanative cross‐coupling through metal‐assisted nucleophilic displacement, which is less explored so far. Thus, a decyanative cross‐coupling of aryl selenocyanate with aryl‐/alkylacetylenes, boronic acids and silanes has been accomplished by a copper‐assisted nucleophilic displacement reaction for an easy access to a series of diaryl, aryl alkyl, aryl vinyl and aryl alkynyl selenides. The best
传统上,金属催化的交叉偶联反应受不同亲核试剂取代卤素,甲苯磺酸盐等离去基团的控制,从而导致碳-碳和碳-杂原子键的形成。除了传统的离去基团在偶联反应中的取代,脱氰交叉偶联也受到了当前的关注。这项工作的目的是通过金属辅助的亲核置换来发展脱氰交叉偶联,到目前为止,这一研究还很少。因此,通过铜辅助的亲核取代反应可以轻松实现一系列二芳基,芳基烷基,芳基乙烯基和芳基炔基硒化物的芳基硒酸芳基酯与芳基/烷基乙炔,硼酸和硅烷的脱氰交叉偶联。 。2,Ag 2 CO 3(20 mol%)和Cs 2 CO 3(1当量)在N-甲基吡咯烷酮(NMP)中于100°C放置8 h 。操作简单,产率高和通用性强的优点使该方法更具吸引力。已经提出了一种机械途径。银在脱氰过程中起关键作用。基于UV,EPR,HRMS和IR分析数据以及对照实验的结果,提出了这种脱氰碳-硒交叉偶联的可能机理。
Enantiodivergent Synthesis of Allenes by Point‐to‐Axial Chirality Transfer
作者:Roly J. Armstrong、Meganathan Nandakumar、Rafael M. P. Dias、Adam Noble、Eddie L. Myers、Varinder K. Aggarwal
DOI:10.1002/anie.201804446
日期:2018.7.2
substituted allenes is described. Highly enantioenriched, point‐chiral boronic esters were synthesized by homologation of α‐seleno alkenyl boronic esters with lithiated carbamates and eliminated to form axiallychiral allene products. By employing either oxidative or alkylative conditions, both syn and anti elimination could be achieved with complete stereospecificity. The process enables the synthesis
Hydroalumination of selenoacetylenes: a versatile generation and reactions of α-aluminate vinyl selenide intermediates in the highly regio and stereoselective synthesis of telluro(seleno)ketene acetals
作者:Palimécio G. Guerrero、Miguel J. Dabdoub、Adriano C.M. Baroni
DOI:10.1016/j.tetlet.2008.04.072
日期:2008.6
(Z)-butylseleno vinyl alanates intermediates which were captured with C4H9TeBr furnishing the (E)-telluro(seleno)ketene acetals exclusively. The isomers with opposite stereochemistry (Z)-telluro(seleno)ketene acetals were obtained by the reduction of phenylseleno acetylenes with lithium di-(isobutyl)-n-butyl aluminate hydride (Zweifel’s reagent) followed by reaction of (E)-phenylseleno vinyl alanates intermediates
丁基硒炔乙炔与DIBAL-H的氢铝化反应,然后添加原位生成的(Z)-丁基硒代乙烯基丙二酸酯中间体,用C 4 H 9 TeBr捕获的正丁基锂,专门提供(E)-碲基(硒代)乙烯酮缩醛。通过用二(异丁基)-正丁基铝酸氢化铝锂(Zweifel试剂)还原苯基硒基乙炔,然后使(E)-苯基硒基乙烯基化合物反应,可获得具有相反立体化学(Z)-碲(硒基)乙烯酮缩醛的异构体用C 4 H 9 TeBr丙酸酯中间体。
Ligand-free, catalytic and regioselective hydroboration of selenoalkynes
作者:Lucas L. Baldassari、Kelvin S. Santos、Camila P. Ebersol、Diogo S. Lüdtke、Angélica V. Moro
DOI:10.1039/d0cy01379j
日期:——
The copper-catalyzed hydroboration of selenoalkynes in a regio- and stereoselective fashion is reported, delivering selenium-containing vinylboronate products in good yields. The reported protocol fills an important gap in the literature with respect to the synthesis of a valuable class of compounds, which is difficult to obtain otherwise.
Synthesis of ketene butyltelluro(phenylseleno)acetals by the Al/Te exchange reaction
作者:Miguel J. Dabdoub、Tânia M. Cassol、Sandro L. Barbosa
DOI:10.1016/0040-4039(95)02333-x
日期:1996.2
Hydroalumination of acetylenic selenides occurs, regiospecifically and the vinyl alanes obtained as intermediates were transformed into ketene butyltelluro (phenylseleno) acetals by the Al/Te exchange reaction using C4H9TeBr as electrophile. The stereoselectivity of the hydroalumination of chalcogeno acetylenes was confirmed by performing the hydrolysis of the vinyl alane intermediates that results in formation of the correponding Z phenylseleno alkenes with good yields.