2570-00-5Relevant academic research and scientific papers
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.
A Palladium-Catalyzed Cascade C-C Activation of Cyclopropenone and Carbonylative Amination: Easy Access to Highly Functionalized Maleimide Derivatives
Nanda, Tanmayee,Ravikumar, P. C.
supporting information, (2020/02/15)
We describe herein the first report on palladium-catalyzed C-C bond activation of cyclopropenone and concomitant carbonylative amination to produce maleimides. The interesting aspect of this reaction is that the sacrificial elimination of carbon monoxide from the substrate is efficiently recaptured by one of the intermediates in the catalytic cycle for the formation of maleimides. 18O isotopic studies confirmed that the source of carbon monoxide is from cyclopropenone.
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%.
The synthesis of Nα-protected amino hydroxamic acids from Nα-protected amino acids employing versatile chlorinating agent CPI-Cl
Vathsala,Srinivasulu,Santhosh,Sureshbabu, Vommina V.
, p. 449 - 457 (2019/03/08)
Racemization free synthesis of Nα-protected amino hydroxamic acids from Nα-protected amino acids employing the versatile chlorinating reagent CPI-Cl has been described in one-pot. The present protocol has shown compability towards urethane protecting groups like Boc, Cbz and Fmoc, and side chain protections of amino acids showed complete tolerance.
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.
Cyclopropenium cation promoted dehydrative glycosylations using 2-deoxy- and 2,6-dideoxy-sugar donors
Nogueira, Jason M.,Nguyen, Son Hong,Bennett, Clay S.
supporting information; experimental part, p. 2814 - 2817 (2011/07/30)
Dehydrative glycosylation reactions using 2-deoxy- and 2,6-dideoxy-sugar donors promoted by a combination of 3,3-dichloro-1,2-diphenylcyclopropene and tetrabutylammonium iodide (TBAI) are described. The reactions are α-selective and proceed under mild con
Cyclopropenium-activated cyclodehydration of diols
Kelly, Brendan D.,Lambert, Tristan H.
supporting information; experimental part, p. 740 - 743 (2011/05/04)
The dehydrative cyclization of diols to cyclic ethers via cyclopropenium activation is described. Using 2,3-diphenylcyclopropene and methanesulfonic anhydride, a series of 1,4-and 1,5-diols are rapidly cyclized to furnish tetrahydrofurans and tetrahydropyrans in high yield. Eleven total substrates are shown, including a gram scale cyclization of a diterpene derivative.
Nucleophilic acyl substitution via aromatic cation activation of carboxylic acids: Rapid generation of acid chlorides under mild conditions
Hardee, David J.,Kovalchuke, Lyudmila,Lambert, Tristan H.
supporting information; experimental part, p. 5002 - 5003 (2010/06/13)
The first example of aromatic cation-activated nucleophilic acyl substitution has been achieved. The conversion of carboxylic acids to their corresponding acid chlorides occurs rapidly in the presence of 3,3-dichlorocyclopropenes via the intermediacy of cyclopropenium carboxylate complexes. The effect of cyclopropene substituents on the rate of conversion is examined. The addition of tertiary amine base is found to dramatically accelerate reaction, and conditions were developed for the preparation of acid sensitive acid chlorides. Preparative scale peptide couplings of two N-Boc amino acids were achieved with this method.
Aromatic cation activation of alcohols: Conversion to alkyl chlorides using dichlorodiphenylcyclopropene
Kelly, Brendan D.,Lambert, Tristan H.
supporting information; scheme or table, p. 13930 - 13931 (2009/12/25)
(Chemical Equation Presented) A novel paradigm for the activation of alcohols toward nucleophilic displacement via formation of cyclopropenium ethers is described. The conversion of a range of alcohol substrates to the corresponding alkyl chlorides occurs rapidly upon treatment with 3,3-dichloro-1,2-diphenylcyclopropene. 1H NMR data support the intermediacy of a cyclopropenium intermediate, and the reaction is demonstrated to proceed primarily via the SN2 mechanism for 1-phenylethanol. A total of 12 examples of substrate scope are provided.
Preparation of 3,3-Bis(phosphoryl)cyclopropenes
Yoshida, Hiroshi,Aoyama, Masanori,Utsumi, Fumitaka,Ogata, Tsuyoshi,Matsumoto, Kiyoshi
, p. 3476 - 3478 (2007/10/02)
The reaction of 1,2-diphenyl- and 1-methyl-2-phenyl-3,3-dichloro- or dibromocyclopropenes with trialkylphosphites, dialkyl phenylphosphonites, and alkyl diphenylphosphinites afforded cyclopropenes with 3,3-diorganophosphorous substituents in moderate yiel
