Syntheses and Reactions in the Cyclobutane Series

Lukina, M. Yu.

doi:10.1070/rc1963v032n12abeh001371

Cited by 16 publications

(8 citation statements)

References 1 publication

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“…The [2 + 2] cycloaddition of alkenes and/or alkynes represents an important strategy for the synthesis of cyclobutane derivatives . A thermally forbidden process by the Woodward−Hoffmann rules, this cycloaddition has been achieved photochemically, by thermal reactions via biradical intermediates, by the use of Lewis acid catalysts, and by the use of transition metal catalysts. − To date, the range of substrates which undergo [2 + 2] reactions with transition metals is rather limited.…”

Section: Four-membered Ring Formationmentioning

confidence: 99%

Transition Metal-Mediated Cycloaddition Reactions

1996

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Contents 1. Introduction 49 2. Three-Membered Ring Formation 50 2.1. [2 + 1] Cycloadditions Using Stoichiometric Amounts of Zinc Carbenoids (Simmons−Smith Type) 50 2.2. [2 + 1] Cycloadditions with Stoichiometric Amounts of Samarium Carbenoids 52 2.3. [2 + 1] Cycloadditions with Transition Metal-Stabilized Alkyl Carbenes of Cu, Pd, Ni, Co, and Rh 52 2.4. Cyclopropanations with Metal Carbenes Derived from R-Diazocarbonyl Compounds 54 2.5. [2 + 1] Cycloadditions with Vinylcarbenes 54 2.6. [2 + 1] Cycloadditions with Palladium Complexes of Oxatrimethylenemethane 56 2.7. Transition Metal-Catalyzed Aziridinations 57 3. Four-Membered Ring Formation 58 3.1. [2 2π + 2 2π ] Cycloadditions of Strained Alkenes with Electron-Deficient Olefins 58 3.2. [2 2π + 2 2π ] Cycloadditions of Strained Alkenes with Acetylenes 59 3.3. Intramolecular [2 2π + 2 2π ] Cycloadditions 60 4. Five-Membered Ring Formation 60 4.1. [3 2σ + 2 2π ] Cycloadditions with Metallacyclobutanes 60 4.2. [3 2σ + 2 2π ] Cycloadditions with Pd−Trimethylenemethane Complexes 61 4.3. Intramolecular [3 2σ + 2 2π ] Cycloadditions with Pd−TMM Complexes 62 4.4. [3 2σ + 2 2π ] Cycloadditions with Methylenecyclopropane 64 4.5. Intramolecular [3 2σ + 2 2π ] Cycloadditions with Methylenecyclopropanes 66 4.6. [3 4π + 2 2π ] Cycloadditions with Metal Carbenoids 67 4.7. [4 4π + 1 2π ] Cycloadditions 69 5. Six-Membered Ring Formation 69 5.1. [2 2π + 2 2π + 2 2π ] Cycloadditions 69 5.2. Acetylene [2 2π + 2 2π + 2 2π ] Cyclotrimerization Reactions 70 5.3. Acetylene−Olefin [2 2π + 2 2π + 2 2π ] Cyclotrimerizations 71 5.4. Hetero [2 2π + 2 2π + 2 2π ] Cyclotrimerizations 72 5.5. Homo-Diels−Alder [2 2π + 2 2π + 2 2π ] Cycloadditions 72 5.6. Bis-Homo-Diels−Alder [2 2π + 2 2π + 2 2π ] Cycloadditions 74 5.7. [3 2π + 3 2σ ] Cycloadditions 74 5.8. [4 4π + 2 2π ] Cycloadditions 75 6. Seven-Membered Ring Formation 78 6.1. [4 4π + 3 2σ ] Cycloadditions 78 6.2. [5 2π+2σ + 2 2π ] Cycloadditions 79 7. Eight-Membered Ring Formation 79 7.1. [2 2π + 2 2π + 2 2π + 2 2π ] Cycloadditions 80 7.2. [4 4π + 2 2π + 2 2π ] Cycloadditions 80 7.3. [4 4π + 4 4π ] Cycloadditions 81 7.4. [6 6π + 2 2π ] Cycloadditions 83 8. Ten-Membered Ring Formation 85 9. Conclusion and Remarks 87 49

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Section: Four-membered Ring Formationmentioning

confidence: 99%

Transition Metal-Mediated Cycloaddition Reactions

1996

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“…On the basis of the examination of palladium sources, solvents, additives, and phosphane ligands, we found that utilizing 0.2 equiv. of [Pd 2 (dba) 3 ] as the catalyst, 0.2 mL of dimethyl sulfoxide (DMSO) as the additive, and PCy 3 as the ligand (0.8 equiv.) at 120°C in toluene for 36 h, provided 2a and 2Јa as a pair of diastereoisomers (5:1) in 76 % yield, which served as the best conditions for this transformation (Scheme 2).…”

Section: Resultsmentioning

confidence: 99%

“…[1,2] However, it should also be noted that release of such strain energy (27 kcal/ mol) [3] is not sufficient for high reactivity. The π character of the ring bonds of a cyclopropane provides the kinetic opportunity to initiate the unleashing of the strain.…”

Section: Introductionmentioning

confidence: 99%

Palladium(0)‐Catalyzed Reaction of Cyclopropylidenecycloalkanes with Carbon Dioxide

et al. 2011

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Cyclopropylidenecycloalkanes, which are highly strained methylenecyclopropane (MCPs) containing a cycloalkane moiety, react with carbon dioxide smoothly to give the corresponding five‐membered lactone derivatives in moderate to good yields through a cyclopropane ring‐opening process in the presence of Pd0 catalyst and PCy3 upon heating under 40 atm of CO2. The relative configuration of the major diastereomers has been determined and a plausible reaction mechanism has also been proposed.

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“…Methylenecyclopropanes (MCPs), as highly strained but readily accessible molecules, can undergo a variety of ring‐opening reactions in the presence of transition metals or Lewis acids because the relief of ring strain can provide a potent thermodynamic driving force 1,2. However, it should also be noted that release of such strain energy (27 kcal/mol)3 is not sufficient for high reactivity. The π character of the ring bonds of a cyclopropane provides the kinetic opportunity to initiate the unleashing of the strain 4.…”

Section: Introductionmentioning

confidence: 99%

Dual‐Luminophore‐Labeled Gold Nanoparticles with Completely Resolved Emission for the Simultaneous Imaging of MMP‐2 and MMP‐7 in Living Cells under Single Wavelength Excitation

Xia

Liu

et al. 2012

Chemistry A European J

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Although considerable effort has been devoted to the design of various nanoprobes for the fluorescent detection of multiple biomarkers in a single assay, they often suffer from emission-overlapping, owing to small Stokes shifts and wide emission spectra, which results in cross-talk and inaccurate quantification. Herein, we report the design and synthesis of a new nanoprobe for multienzyme detection with completely resolved emission peaks under single-wavelength excitation. The probe was assembled by attaching a cleavable peptide spacer, which was comprised from a matrix metalloproteinase-2 (MMP-2) substrate and a MMP-7 substrate, onto the surface of gold nanoparticles (AuNPs) through cysteine residues. A lanthanide complex, BCTOT-Eu(III) (BCTOT=1,10-bis(5'-chlorosulfo-thiophene-2'-yl)-4,4,5,5,6,6,7,7-octafluorodecane-1,3,8,10-tetraone), and 7-amino-4-methylcoumarin (AMC) were attached to the N terminus and the C terminus of the peptide, respectively. In the presence of one or both targeting enzymes, the substrate was cleaved and fluorescence resonance energy transfer (FRET) between the dyes and AuNPs was prohibited, thereby resulting in the dramatic fluorescence emission of dyes. Importantly, there was no emission cross-talk between the two dyes, thereby ensuring accurate detection of each enzyme. Based on this, the simultaneous fluorescence image of MMP-2 and MMP-7 was accomplished in living cells under single wavelength excitation. The apparent differences in the fluorescence imaging indicated distinct differences between the expression levels of MMPs between the human normal liver cells and the human hepatoma cells.

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Syntheses and Reactions in the Cyclobutane Series

Cited by 16 publications

References 1 publication

Transition Metal-Mediated Cycloaddition Reactions

Transition Metal-Mediated Cycloaddition Reactions

Palladium(0)‐Catalyzed Reaction of Cyclopropylidenecycloalkanes with Carbon Dioxide

Dual‐Luminophore‐Labeled Gold Nanoparticles with Completely Resolved Emission for the Simultaneous Imaging of MMP‐2 and MMP‐7 in Living Cells under Single Wavelength Excitation

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