1133321-55-7Relevant articles and documents
Selective dimerization of terminal acetylenes in the presence of PEPPSI precatalysts and relative chloro- and hydroxo-bridged N-heterocyclic carbene palladium dimers
Ostrowska, Sylwia,Szymaszek, Natalia,Pietraszuk, Cezary
, p. 63 - 69 (2018)
Highly regio- and stereoselective dimerization of terminal acetylenes occurs in the presence of [PdCl2(IPr)(3-chloropyridine)], other members of the family of PEPPSI precatalysts and the structurally related N-heterocyclic carbene palladium dim
The Choice Is Yours: Using Liquid-Assisted Grinding to Choose between Products in the Palladium-Catalyzed Dimerization of Terminal Alkynes
Chen, Longrui,Regan, Mark,Mack, James
, p. 868 - 872 (2016)
Herein, we report on the dimerization of terminal alkynes using various palladium catalysts under solvent-free mechanochemical conditions. When tetrakis(triphenylphosphine)palladium(0) was employed as the catalyst, we observed the 1,3-butadiyne as the major product. However, when we employed bis(triphenylphosphine)palladium(II) dichloride as the catalyst, we observed the trans-enyne as the major product. When we used a polymer-supported bis(triphenylphosphine)palladium(II) dichloride catalyst under liquid-assisted grinding conditions, we discovered the ability to tune the catalyst to generate either the diyne or trans-enyne as the major product, depending on the grinding medium.
Stereo- A nd regioselective dimerization of alkynes to enynes by bimetallic syn-carbopalladation
Pfeffer, Camilla,Wannenmacher, Nick,Frey, Wolfgang,Peters, René
, p. 5496 - 5505 (2021/05/31)
Enynes are important motifs in bioactive compounds. They can be synthesized by alkynea'alkyne couplings for which a number of mechanisms have been suggested depending on catalyst type and dominant product isomers. Regarding bimetallic pathways, hydrometalations and anti-carbopalladations have been discussed to account for the formation of geminally substituted and (Z)-configured enynes, respectively. Here we report a bimetallic alkynea'alkyne coupling that yields (E)-configured enynes. An unusual type of acetylide Pd bridging was found in putative catalytic intermediates which is arguably responsible for the regio- A nd stereochemical reaction outcome. Mechanistic studies suggest that a double μa'κ:η2 acetylide bridging enables a bimetallic syn-carbometalation. Interestingly, depending on the reaction conditions, it is also possible to form the geminal regioisomer as major product with the same catalyst. This regiodivergent outcome is explained by bi-versus monometallic reaction pathways.
Ligand-Controlled Diastereoselective Cobalt-Catalysed Hydroalkynylation of Terminal Alkynes to E- or Z-1,3-Enynes
Weber, Sebastian M.,Queder, Jona,Hilt, Gerhard
supporting information, p. 12129 - 12133 (2020/09/09)
A diastereoselective hydroalkynylation of terminal alkynes to form the head-to-head dimerization products by two different cobalt-phosphine catalyst system is reported. The use of the bidentate ligand dppp and additional triphenylphosphine led to the selective formation of the (E)-1,3-enynes (E:Z>99:1) in good to excellent yields, while the tridentate ligand TriPhos led to the corresponding (Z)-1,3-enynes in moderate to good yields with excellent stereoselectivities (up to E:Z=1:99). Both pre-catalysts are easy to handle, because of their stability under atmospheric conditions. The optimized reaction conditions were identified by the Design of Experiments (DoE) approach, which has not been used before in cobalt-catalysed reaction optimisation. DoE decreased the number of required reactions to a minimum.
Sequential Transformation of Terminal Alkynes to 1,3-Dienes by a Cooperative Cobalt Pyridonate Catalyst
Zhuang, Xuewen,Chen, Jia-Yi,Yang, Zhuoyi,Jia, Mengjing,Wu, Chengjuan,Liao, Rong-Zhen,Tung, Chen-Ho,Wang, Wenguang
supporting information, p. 3752 - 3759 (2019/11/13)
We describe the cobalt(II) catalyst 1 bearing a phosphinopyridonate ligand for sequential transformation of aryl terminal alkynes to (E,Z)-1,3-dienes with excellent stereoselectivity. By cooperative metal-ligand reactivity, 1 reacts readily with the termi
