Copper catalyzed/mediated direct B–H alkenylation/alkynylation in carboranes
作者:Yu Chen、Yik Ki Au、Yangjian Quan、Zuowei Xie
DOI:10.1007/s11426-018-9388-3
日期:2019.1
B–H functionalization has been achieved. Under the assistance of a bidentate directing group, Cu-catalyzed [4+2] annulation of carboranyl amides with internal alkynes affords unprecedented C,B-substituted carborane-fused-pyridone derivatives, whereas the use of terminal alkynes leads to B–H/C(sp)–H dehydrocoupling products. The isolation and structural identification of a notably stable Cu(I) intermediate
Electrochemical esterification reaction of alkynes with diols <i>via</i> cleavage of carbon–carbon triple bonds without catalyst and oxidant
作者:Pei-Long Wang、Hui-Zhi Shen、Hui-Hui Cheng、Hui Gao、Pin-Hua Li
DOI:10.1039/d0gc02193h
日期:——
as it is catalyst-free, oxidant-free, and additive-free and shows atom-economy. This is the first example of an electrochemical reaction via cleavage of carbon–carbon triple bonds. Meanwhile, this is also the first example of a carbon–carbon triple bond cleavage reaction of alkynes with diols.
beta-unsaturated oximes and internalalkynes has been developed using [Cp*RhCl2](2)-CsOPiv as the catalyst system. The present transformation is carried out by a redox-neutral sequence of vinylic C-H rhodation, alkyne insertion, and C-N bond formation of the putative vinyl rhodium intermediate with the oxime nitrogen, where the N-Obond of oxime derivatives could work as an internaloxidant to maintain the catalytic
使用 [Cp*RhCl2](2)-CsOPiv 作为催化剂体系开发了一种从 α、β-不饱和肟和内部炔烃合成高度取代的吡啶的方法。目前的转化是通过乙烯基 CH 化、炔插入和 CN 键形成的氧化还原中性序列与肟氮形成推定的乙烯基铑中间体,其中肟衍生物的 NO 键可以作为内部氧化剂来维持催化循环。
Palladium‐Catalyzed Carbonylative Annulation of 1‐Hydroxy‐
<i>o</i>
‐Carborane and Internal Alkynes via Regioselective B‐H Activation
作者:Yik Ki Au、Yangjian Quan、Zuowei Xie
DOI:10.1002/asia.202000642
日期:2020.7.16
carbonylative‐annulation of 1‐hydroxy‐o‐carborane, internalalkyne and carbon monoxide has been achieved via direct and regioselective cage B−H activation. A class of C,B‐substituted carborano‐coumarin derivatives with potential applications in pharmaceuticals were facilely prepared in moderate to high yields with excellent chemoselectivity and regioselectivity. A plausible reaction mechanism including CO
A palladium‐catalyzed heptagon‐forming annulation reaction between 1‐halo‐8‐arylnaphthalene and diarylacetylene is reported. The reaction is promoted using a catalytic system comprised of Pd(OAc)2, moderately electron‐deficient triarylphosphine P(4‐ClC6H4)3, and Ag2CO3 to afford benzo[4,5]cyclohepta[1,2,3‐de]naphthalene derivatives in moderate to good yields, in preference to fluoranthene as a competing
据报道,1-卤代-8-芳基萘与二芳基乙炔之间存在钯催化的七边形环化反应。使用由Pd(OAc)2,中度缺电子的三芳基膦P(4-ClC 6 H 4)3和Ag 2 CO 3组成的催化体系促进反应,得到苯并[4,5]环庚[1,2 ,3-德在中度至良好的产率]萘衍生物,优先于荧蒽作为竞争副产物。也可以实现双重环化,以获取一种新型的嵌入七边形的多环芳烃化合物。