Oxidizing Morita–Baylis–Hillman adducts towards vicinal tricarbonyl compounds

Santos, Marília S.; Coelho, Fernando

doi:10.1039/c2ra01267g

Cited by 42 publications

(19 citation statements)

References 59 publications

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“…We started our investigation by preparing substrate 1 a through the oxidation of a Morita–Baylis–Hillman (MBH) adduct by employing Dess–Martin periodinane (DMP). This methodology was based on previous reports in the literature employing hypervalent iodine reagents and allowed access to the desired compound in excellent yield (99 %) and without the need for purification by column chromatography . This dicarbonyl substrate was then reacted with potassium trichloroacetate in the presence of DMSO (Scheme ), which selectively lead to the 1,1‐dichlorocyclopropyl adduct (product 2 a ).…”

Section: Resultsmentioning

confidence: 99%

gem‐Dichlorocyclopropanation of Dicarbonyl Derivatives

Batista

Castro

Carpanez

et al. 2019

Chemistry A European J

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An ovel methodology for the 1,1-dichlorocyclopropanation of dicarbonyl conjugated olefins was described. The developed protocol is simple and uses readily accessible starting materials, allowing the isolation of the desired adducts in moderate to excellent yields (up to 99 %). Furthermore, the reaction tolerated scale up to the gram scale;thus highlighting the syntheticp otentialo ft his transformation.Controle xperimentsa nd DFT studies revealed that the reaction proceeded through aM ichael-initiated ring-closure process, in which reactiont emperature played ac rucial role. Finally,t hese gem-dichlorocyclopropanes were also employed in the preparation of at risubstituted naphthyl derivative and ad iastereoselective reduction was also demonstrated.Scheme1.Previousstudies and our proposal for the gem-dichlorocyclopropanationofo lefins. TMS = trimethylsilyl.[a] G.The reaction mixture was purified through column chromatography on silica gel (elution:h exane/CH 2 Cl 2 1:1) to afford product 2l as ac olorless oil (59 mg, 99 %).

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Section: Resultsmentioning

confidence: 99%

gem‐Dichlorocyclopropanation of Dicarbonyl Derivatives

Batista

Castro

Carpanez

et al. 2019

Chemistry A European J

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“…The hydroxyl groups in 2a-2g and 2j were oxidized using IBX [46], and then the conjugated double bond was reduced using the borane dimethyl sulfide complex (Scheme 5; Table 2). Boranes have already been used in combination with silanes as reducing agents for some particular type of double bonds [47][48][49][50][51]; however, the only example where the borane dimethyl sulfide complex was used to reduce electronically poor double bonds was reported some years ago for cyclic vinylphosphine oxides or dihydrophosphole oxides [52][53][54].…”

Section: Resultsmentioning

confidence: 99%

Morita–Baylis–Hillman adducts as building blocks of heterocycles: a simple approach to 4-substituted pyrazolones, and mechanism investigation via ESI–MS(/MS)

et al. 2015

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We describe herein an efficient approach for the preparation of 4-substituted 2,3-dihydro-1H-pyrazol-3-ones starting from Morita-Baylis-Hillman adducts. These heterocycles were obtained in two or three steps as single isomers with moderate to good overall yields. One efficient and alternative methodology for the synthesis of a-methylb-ketoesters is also reported (up to 91 % yield). Additionally, the mechanism of formation of pyrazolones was investigated employing ESI-MS/MS reaction monitoring. Graphical abstract

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“…Only in the case of quinolones 4.8 and 4.19 with COCH 3 and SO 2 Ph groups, respectively, at C‐3, the yields were 50%. Benzylic oxidation of Baylis–Hillman adducts with IBX to 1,3‐dicarbonyl compounds is known, and use of such intermediates for aza‐Michael–S N Ar steps could be an alternative approach to improve the yields of 4.8 and 4.19 34. To have an aldehyde group at the C‐3 position, the THQ intermediate (e.g., 3.1 ) can be first reduced using NaBH 4 and then subjected to oxidation using IBX.…”

Section: Resultsmentioning

confidence: 99%

Isolation and Enrichment of Pathogens with a Surface‐Modified Aluminium Chip for Raman Spectroscopic Applications

et al. 2013

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We developed a Raman-compatible chip for isolating microorganisms from complex media. The isolation of bacteria is achieved by using antibodies as capture molecules. Due to the very specific interaction with the targets, this approach is promising for isolation of bacteria even from complex matrices such as body fluids. Our choice of capture molecules also enabled the investigation of samples containing yet unidentified bacteria, as the antibodies can capture a large variety of bacteria based on their analogue cell wall surface structures. The capability of our system is demonstrated for a broad range of different Gram-positive and Gram-negative germs. Subsequent identification is done by recording Raman spectra of the bacteria. Further, it is shown that classification with chemometric methods is possible.

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Oxidizing Morita–Baylis–Hillman adducts towards vicinal tricarbonyl compounds

Cited by 42 publications

References 59 publications

gem‐Dichlorocyclopropanation of Dicarbonyl Derivatives

gem‐Dichlorocyclopropanation of Dicarbonyl Derivatives

Morita–Baylis–Hillman adducts as building blocks of heterocycles: a simple approach to 4-substituted pyrazolones, and mechanism investigation via ESI–MS(/MS)

Isolation and Enrichment of Pathogens with a Surface‐Modified Aluminium Chip for Raman Spectroscopic Applications

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