Iron-Catalyzed <i>gem</i>
-Specific Dimerization of Terminal Alkynes
作者:Qiuming Liang、Kimberly M. Osten、Datong Song
DOI:10.1002/anie.201700904
日期:2017.5.22
We report a gem-specific homo- and cross-dimerization of terminalalkynes catalyzed by a well-defined iron(II) complex containing Cp* and picolyl N-heterocyclic carbene (NHC) ligands, and featuring a piano-stool structure. This catalytic system requires no additives and is compatible with a broad range of substrates, including those with polar functional groups such as NH and OH.
Piano-Stool Iron Complexes as Precatalysts for <i>gem</i>-Specific Dimerization of Terminal Alkynes
作者:Qiuming Liang、Kasumi Hayashi、Karolina Rabeda、Jose L. Jimenez-Santiago、Datong Song
DOI:10.1021/acs.organomet.0c00271
日期:2020.6.22
A series of piano-stool Fe–NHC complexes have been prepared and characterized. The NHC ligands used herein possess a benzyl and a mesityl wingtip groups and have different electronic structures within the NHC rings. The catalytic activities of these Fe complexes have been examined for the homodimerization of terminal alkynes.
Carboxylate Switch between Hydro- and Carbopalladation Pathways in Regiodivergent Dimerization of Alkynes
作者:Olga V. Zatolochnaya、Evgeniy G. Gordeev、Claire Jahier、Valentine P. Ananikov、Vladimir Gevorgyan
DOI:10.1002/chem.201402809
日期:2014.7.28
regiodivergent palladium‐catalyzed dimerization of terminalalkynes is presented. Employment of N‐heterocyclic carbene‐based palladium catalyst in the presence of phosphine ligand allows for highly regio‐ and stereoselective head‐to‐head dimerization reaction. Alternatively, addition of carboxylate anion to the reaction mixture triggers selective head‐to‐tail coupling. Computational studies suggest that reaction
Reactivity Switch Enabled by Counterion: Highly Chemoselective Dimerization and Hydration of Terminal Alkynes
作者:Caixia Xu、Weiyuan Du、Yi Zeng、Bin Dai、Hao Guo
DOI:10.1021/ol403684a
日期:2014.2.7
A counterion-controlled reactivity tuning in Pd-catalyzed highly chemoselective and regioselective dimerization and hydration of terminalalkynes is reported. The use of acetate as counterion favors the formation of an alkenyl alkynyl palladium intermediate which forms hitherto less reported 1,3-diaryl-substituted conjugated enynes after reductive elimination. Using chloride, which is a better leaving
A ruthenium-based catalytic system with switchable selectivity between cyclotrimerization and enyne metathesis/Diels–Alder reactions of terminal alkynes
作者:Solmaz Karabulut、Begüm Sariaslan、Bengi Özgün Öztürk
DOI:10.1016/j.catcom.2013.06.023
日期:2013.11
cyclotrimerization and crossenynemetathesis. The cyclotrimerization reaction of phenylacetylene catalyzed by [RuCl2(p-cymene)]2 can be switched to enynemetathesis by the introduction of a sterically hindered N-heterocyclic carbene. The 1,3-diene formed during this reaction reacts with dienophiles to form the Diels–Alder adduct. A practical one-pot synthesis method, utilizing enynemetathesis/Diels–Alder reactions