70871-45-3Relevant academic research and scientific papers
A one-pot isomerization-arylation of 2,3-epoxycyclohexanone under controlled microwave heating
Svennebring, Andreas,Garg, Neeraj,Nilsson, Peter,Hallberg, Anders,Larhed, Mats
, p. 4720 - 4725 (2007/10/03)
A fast one-pot method has been developed for the direct preparation of 3-aryl-1,2-cyclohexanediones from 2,3-epoxycyclohexanone via a microwave-assisted tandem epoxy ketone isomerization-Heck arylation reaction. The preparative microwave-assisted reactions were performed preferentially in 50% aqueous poly(ethylene glycol) utilizing sodium acetate as the base. Within 5-30 min of directed microwave heating, employing less than 0.05 mol % of palladium acetate and no phosphine ligand, up to 72% yield of C3-arylated dike tones was isolated in an overall environmentally benign process. On the basis of the chemical reactivity of proposed intermediates, a reaction pathway is proposed where the acetate base promotes the rearrangement of the 2,3-epoxycyclohexanone into the active mono-enol form of 1,2-cyclohexanedione. An alternative classically heated procedure for isomerization-C3-arylation of 2,3-epoxycyclohexanone in DMF is also reported.
Radical chain reactions of α-azido ketones with tributyltin hydride: Reduction vs nitrogen insertion and 1,2-hydrogen shift in the intermediate N-stannylaminyl radicals
Benati, Luisa,Leardini, Rino,Minozzi, Matteo,Nanni, Daniele,Spagnolo, Piero,Strazzari, Samantha,Zanardi, Giuseppe,Calestani, Gianluca
, p. 3485 - 3492 (2007/10/03)
The radical chain reactions of a variety of acyclic and cyclic α-azido ketones with tributyltin hydride have been investigated. The derived N-(tributylstannyl)aminyl radicals normally undergo H-abstraction reaction yielding corresponding amines, and thence symmetrical pyrazines by subsequent self-condensation, in competition with 1,2-H-migration from the α-carbon to nitrogen leading to α-imino ketone decomposition products with loss of the chain-carrying tributyltin radical. The noteworthy occurrence of a quite uncommon radical 1,2-hydrogen-atom shift is considered to be largely due to consequent formation of a highly stable, captodative carbon-centred radical. In contrast with our previous N-stannylaminyl radicals produced from α-azido-β-keto esters, the present aminyl congeners give poor amounts (or even none) of nitrogen-inserted amides/lactams, which are envisaged to arise from intramolecular three-membered cyclisation onto the ketone moiety followed by β-scission of the resultant alkoxyl radical. It is inferred that adequate stabilisation of the eventual ring-opened carbon radical be a major factor for the successful outcome of the regiospecific nitrogen insertion process. Evidence is also presented that chemoselective attack of tris(trimethylsilyl)silyl radical to the ketone oxygen of an α-azido ketone gives rise to deazidation as a likely consequence of β-elimination of azidyl radical by the ensuing α-silyloxyalkyl radical. X-Ray crystal structure analyses of the bromo ketone 5a, the azido ketone 5b, the caprolactam 22, and the pyrazine 26 have been performed.
Conjugate addition of lithium diorganocuprate reagents to the enol tosylate of a 1,2-diketone
Charonnat,Mitchell,Keogh
, p. 315 - 318 (2007/10/02)
The conjugate addition of lithium diorganocuprate reagents to the enol tosylate of 1,2-cyclohexanedione has been investigated. The intermediate enolates eliminate para-toluenesulfinate ion to generate the alkylated 1,2-dicarbonyl system.
A New Synthesis of 3-Alkyl-1,2-cyclohexanediones from 2-Alkylcyclohexanones Using Iodine/Copper(II) Acetate
Horiuchi, C. Akira,Kiyomiya, Hiroshi,Takahashi, Masaaki,Suzuki, Yasuto
, p. 785 - 786 (2007/10/02)
The reactions of 2-alkyl-, 2,5-dimethyl-, and 3,3,5-trimethylcyclohexanone with iodine/copper(II) acetate in boiling aqueous acetic acid gave the respective 3-alkyl-, 3,6-dimethyl-, and 3,5,5-trimethyl-1,2-cyclohexanediones in 40-70percent yields.This new
SWERN OXIDATION OF α-KETOLS TO α-DIKETONES
Kawada, Kenji,Gross, Raymond S.,Watt, David S.
, p. 777 - 786 (2007/10/02)
The Swern oxidation of acyclic and cyclic α-ketols delivered α-diketones or the tautomeric diosphenols in good yield.
Photochemical Reactivity of α-Sulfonyloxy Enones: An Easy Method for Arylation of 1,2-Diketones
Feigenbaum, Alexandre,Pete, Jean-Pierre,Scholler, Denise
, p. 2355 - 2360 (2007/10/02)
3-Aryl-1,2-cyclohexanediones 4 are prepared conveniently by photolysis of the corresponding 2-((arylsulfonyl)oxy)cyclohex-2-enones 1.The reaction was shown to occur from a triplet excited state.A biphotonic process involving the normal photo-Fries product 14 as an intermediate was ruled out by preparing and irradiating this compound.The difference of reactivity between 1 and 2-((arylsulfonyl)amido)cyclohexenones is discussed.
