14070-68-9Relevant academic research and scientific papers
β-Diazocarbonyl Compounds: Synthesis and their Rh(II)-Catalyzed 1,3 C?H Insertions
Jiang, Liyin,Wang, Zhaofeng,Armstrong, Melanie,Suero, Marcos G.
supporting information, p. 6177 - 6184 (2021/02/01)
Herein, we describe the first electrophilic diazomethylation of ketone silyl enol ethers with diazomethyl-substituted hypervalent iodine reagents that gives access to unusual β-diazocarbonyl compounds. The potential of this unexplored class of diazo compounds for the development of new reactions was demonstrated by the discovery of a rare Rh-catalyzed intramolecular 1,3 C?H carbene insertion that led to complex cyclopropanes with excellent stereocontrol.
Binuclear copper complexes and their catalytic evaluation
Das, Raj K.,Sarkar, Mithun,Wahidur Rahaman,Doucet, Henri,Bera, Jitendra K.
experimental part, p. 1680 - 1687 (2012/05/20)
Two binuclear copper complexes [{CuI(L1)} 2][OTf]2 (1) and [{CuII(L2)Cl} 2] (2) have been synthesized and structurally characterized. The reaction of [{(5,7-dimethyl-1,8-naphthyr
The direct preparation of functionalised cyclopropanes from allylic alcohols or α-hydroxyketones using tandem oxidation processes
McAllister, Graeme D.,Oswald, Magalie F.,Paxton, Richard J.,Raw, Steven A.,Taylor, Richard J.K.
, p. 6681 - 6694 (2007/10/03)
New manganese dioxide-mediated tandem oxidation processes (TOPs) have been developed, which facilitate the direct conversion of allylic alcohols and α-hydroxyketones into polysubstituted functionalised cyclopropanes. In the simplest version, the oxidation of an allylic alcohol is carried out in the presence of a stabilised sulfurane, and the intermediate α,β-unsaturated carbonyl compound undergoes in situ cyclopropanation. By using a combination of stabilised phosphorane and sulfurane, the direct conversion of allylic alcohols or α-hydroxyketones into functionalised cyclopropanes is achieved, with in situ cyclopropanation being followed by Wittig olefination, or vice versa. The application of these methods to a formal synthesis of the lignan (±)-picropodophyllone, and to novel analogues of the insecticide allethrin II, is described.
The formation of cyclopropane derivatives bearing 1,2-dicarbonyl groups through tandem Michael-Favorskii-type reactions with (E) -β-styrylselenonium triflate
Watanabe, Shin-Ichi,Nakayama, Ippei,Kataoka, Tadashi
, p. 1493 - 1496 (2007/10/03)
A novel tandem Michael-Favorskii-type reaction is described. Treatment of active methylene carbanions, prepared by the reaction of NaH and active methylene compounds, with (E)-β-styrylselenonium triflate in DMF at 70°C for 3 h gave cyclopropane derivatives bearing 1,2-dicarbonyl groups in moderate to good yields. On the other hand, the carbanions derived from malonates reacted with the selenonium salt to afford 1,1-dicarbonylcyclopropane compounds in good yields. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.
Tandem oxidation processes for the preparation of functionalized cyclopropanes
Oswald, Magalie F.,Raw, Steven A.,Taylor, Richard J. K.
, p. 3997 - 4000 (2007/10/03)
(Chemical Equation Presented) A novel manganese dioxide-mediated tandem oxidation process (TOP) has been developed which allows the direct conversion of allylic alcohols into cyclopropanes, the intermediate aldehydes being trapped in situ with a stabilized sulfur-ylide. This methodology has been applied successfully to a variety of allylic alcohols and to a formal synthesis of the simple, naturally occurring lignan, (±)-picropodophyllone.
Reactions of aliphatic diazo compounds: III. Reaction of ethyl diazoacetate with 1,3-diarylpropenones
Molchanov,Lykholai,Kostikov
, p. 1517 - 1521 (2007/10/03)
Ethyl diazoacetate adds to 1,3-diarylpropenones in a regioselective fashion to give intermediate 4,5-dihydro-3W-pyrazole derivative; 1,3-hydride shift in the latter leads to formation of isomeric ethyl 4-aryl-5-aroyl-4,5-dihydro-1H-pyrazole-3-carboxylate
Catalytic cyclopropanation of electron deficient alkenes mediated by chiral and achiral sulfides: Scope and limitations in reactions involving phenyldiazomethane and ethyl diazoacetate
Aggarwal, Varinder K.,Smitha, Helen W.,Hynd, George,Jones, Ray V.H.,Fieldhouse, Robin,Spey, Sharon E.
, p. 3267 - 3276 (2007/10/03)
Phenyldiazomethane reacts with electron deficient alkenes in the presence of catalytic amounts of transition metal catalyst [Rh2(OAc)4 was better than Cu(acac)2] and catalytic amounts of sulfide to give cyclopropanes. Pentamethylene sulfide was found to be superior to tetrahydrothiophene and the optimum solvent was toluene. Under these optimised conditions a range of enones were cyclopropanated in high yields. Cyclic enones and acrylates were not successful in this process. The use of the chiral 1,3-oxathiane derived from camphorsulfonyl chloride in 2 steps in this process furnished cyclopropanes in good yield and very high enantiomeric excess (>97% ee). The absolute stereochemistry of cyclopropane 10 was proven by X-ray analysis and the origin of the stereochemical induction has been rationalised. Extension of this work to include diazoesters was partially successful. Again pentamethylene sulfide was found to be superior to tetrahydrothiophene, but this time both Rh2(OAc)4 and Cu(acac)2 were found to be equally effective. Enones, fumarates and unsaturated nitro compounds worked well but simple acrylates and unsaturated aldehydes were not effective substrates. Control experiments were conducted in which the stabilised ylide was isolated and reacted with the less successful substrates and, whilst unsaturated aldehydes still gave low yields, simple acrylates gave high yields of the corresponding cyclopropane. The use of the chiral 1,3-oxathiane was not successful with these more stable diazo compounds.
An Improved Method for the Synthesis of Cyclopropyl Ketoesters
Rai, K. M. Lokanatha,Anjanamurthy, C.,Radhakrishna, P. M.
, p. 1273 - 1277 (2007/10/02)
A simple and versatile method for the synthesis of cyclopropyl ketoesters starting from chalcones and ethyl cyanoacetate in benzene using sodium powder as base is described.
Further Investigations into the Mechanism of the Acid Catalysed Rearrangement of Aryl Substituted Cyclopropyl Ketones
Hantawong, Kesra,Murphy, William S.
, p. 2520 - 2547 (2007/10/02)
The acid catalysed rearrangement of a number of aryl cyclopropyl ketones (2) to tetralones (3) were investigated in situ by 1H and 13C n.m.r. spectroscopy.The formation of oxycyclopentenyl intermediates (4) were observed.The involvement of a concurrent el
