Ruthenium-catalyzed [2+2] cycloadditions of bicyclic alkenes and ynamides
作者:Karine Villeneuve、Nicole Riddell、William Tam
DOI:10.1016/j.tet.2005.11.081
日期:2006.4
Ruthenium-catalyzed [2+2] cycloadditionsbetweenbicyclicalkenes and ynamides were investigated. The ynamide moiety was found to be compatible with the ruthenium-catalyzedcycloaddition conditions giving the corresponding cyclobutene cycloadducts in moderate to good yields (up to 97%). Diastereoselective cycloaddition utilizing chiral cyclic ynamides were also examined and a low to moderate level
Radical Germylzincation of α-Heteroatom-Substituted Alkynes
作者:Karen de la Vega-Hernández、Elise Romain、Anais Coffinet、Kajetan Bijouard、Geoffrey Gontard、Fabrice Chemla、Franck Ferreira、Olivier Jackowski、Alejandro Perez-Luna
DOI:10.1021/jacs.8b09851
日期:2018.12.19
The regio- and stereoselectiveaddition of germanium and zinc across the C-C triple bond of nitrogen-, sulfur-, oxygen-, and phosphorus-substituted terminal and internal alkynes is achieved by reaction with a combination of R3GeH and Et2Zn. Diagnostic experiments support a radical-chain mechanism and the β-zincated vinylgermanes that show exceptional stability are characterized by NMR spectroscopy
通过与 R3GeH 和 Et2Zn 的组合反应,锗和锌在氮、硫、氧和磷取代的末端和内部炔烃的 CC 三键上的区域和立体选择性加成。诊断实验支持自由基链机制,并通过 NMR 光谱和 X 射线晶体学表征显示出异常稳定性的 β-锌化乙烯基锗烷。这种新的自由基锗基锌化反应的独特之处在于,形成的 C(sp2)-Zn 键仍然可用于随后的原位 Cu(I)-或 Pd(0)-介导的 CC 或 C-杂原子键的形成,同时保留双键几何。
Palladium‐Catalyzed Silylcyanation of Ynamides: Regio‐ and Stereoselective Access to Tetrasubstituted 3‐Silyl‐2‐Aminoacrylonitriles
作者:Pierre Hansjacob、Frédéric R. Leroux、Vincent Gandon、Morgan Donnard
DOI:10.1002/anie.202200204
日期:2022.3.28
Tetrasubstituted 2-aminoacrylonitriles (α-enaminonitriles) are underinvestigated building blocks due to the lack of methodologies to synthesize them in a controlled manner. A general access to these valuable scaffolds accompanied by mechanistic investigations and DFT calculations is described. This highly regio- and stereoselective strategy relies on the use of the first intermolecular silylcyanation
Ruthenium-Catalyzed [2 + 2] Cycloadditions of Ynamides
作者:Nicole Riddell、Karine Villeneuve、William Tam
DOI:10.1021/ol0512841
日期:2005.8.1
[GRAPHICS]Ruthenium-catalyzed [2 + 2] cycloadditions between norbornene and ynamides were investigated. The ynamide moiety was found to be compatible with the ruthenium-catalyzed cycloaddition conditions, giving the corresponding cyclobutene cycloadducts in moderate to good yields (up to 97%).