2570-00-5Relevant articles and documents
Fully Substituted Conjugate Benzofuran Core: Multiyne Cascade Coupling and Oxidation of Cyclopropenone
Yao, Liangliang,Hu, Qiong,Bao, Li,Zhu, Wenjing,Hu, Yimin
supporting information, p. 4971 - 4975 (2021/06/30)
An unprecedented C═C double bond cleavage of cyclopropenone and dioxygen activation by multiyne cascade coupling has been developed. This chemistry provides a novel, simple, and efficient approach to synthesize fully substituted conjugate benzofuran derivatives from simple substrates under mild conditions. The density functional theory (DFT) calculations reveal that the unique homolytic cleavages of cyclopropenone and molecular oxygen are crucial to the success of this reaction.
Cyclopropenium-Activated DMSO for Swern-Type Oxidation
Guo, Tianfo,Gao, Yu,Li, Zhenjiang,Liu, Jingjing,Guo, Kai
supporting information, p. 329 - 332 (2019/02/12)
Swern oxidation is widely used to convert alcohols into their corresponding carbonyl compounds. However, the conventional method with use of the volatile oxalyl chloride as an activator requires the reaction to be conducted below -60 °C. We discovered that 3,3-dichloro-1,2-diphenylcyclopropene (DDC) can be used as a new activator for Swern-type oxidations of alcohols, which can be conducted at -20 °C. This new protocol features mild and fast reactions with easy operation. Furthermore, the activator DDC is easy to handle, and diphenylcyclopropenone can be recovered quantitively. This new type of Swern oxidation shows a broad scope of substrates including benzylic, allylic, aliphatic, and biobased alcohols, and gives high yields of up to 93%.
Cyclopropenylidene carbene ligands in palladium catalysed coupling reactions: Carbene ligand rotation and application to the Stille reaction
Chotima, Ratanon,Dale, Tim,Green, Michael,Hey, Thomas W.,McMullin, Claire L.,Nunns, Adam,Guy Orpen,Shishkov, Igor V.,Wass, Duncan F.,Wingad, Richard L.
experimental part, p. 5316 - 5323 (2011/06/27)
Reaction of [Pd(PPh3)4] with 1,1-dichloro-2,3- diarylcyclopropenes gives complexes of the type cis-[PdCl2(PPh 3)(C3(Ar)2)] (Ar = Ph 5, Mes 6). Reaction of [Pd(dba)2] with 1,1-dichloro-2,3-diarylcyclopropenes in benzene gave the corresponding binuclear palladium complexes trans-[PdCl2(C 3(Ar)2)]2 (Ar = Ph 7, p-(OMe)C 6H48, p-(F)C6H49). Alternatively, when the reactions were performed in acetonitrile, the complexes trans-[PdCl2(NCMe)(C3(Ar)2)] (Ar = Ph 10, p-(OMe)C6H411 and p-(F)C6H4) 12) were isolated. Addition of phosphine ligands to the binuclear palladium complex 7 or acetonitrile adducts 11 and 12 gave complexes of the type cis-[PdCl 2(PR3)(C3(Ar)2)] (Ar = Ph, R = Cy 13, Ar = p-(OMe)C6H4, R = Ph 14, Ar = p-(F)C 6H4, R = Ph 15). Crystal structures of complexes 6·3.25CHCl3, 10, 11·H2O and 12-15 are reported. DFT calculations of complexes 10-12 indicate the barrier to rotation about the carbene-palladium bond is very low, suggesting limited double bond character in these species. Complexes 5-9 were tested for catalytic activity in C-C coupling (Mizoroki-Heck, Suzuki-Miyaura and, for the first time, Stille reactions) and C-N coupling (Buchwald-Hartwig amination) showing excellent conversion with moderate to high selectivity.
