- Synthesis of allenes via gold-catalyzed intermolecular reaction of propargylic alcohols and aromatic compounds
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Functionalized allenes are efficiently synthesized in moderate to high yield from gold-catalyzed intermolecular reaction of propargylic alcohols and aromatic compounds. The user-friendly process could be conducted under mild reaction conditions with easily accessible starting materials.
- Xu, Cheng-Fu,Xu, Mei,Yang, Liu-Qing,Li, Chuan-Ying
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p. 3010 - 3016
(2012/05/05)
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- Silver(i)-mediated highly enantioselective synthesis of axially chiral allenes under thermal and microwave-assisted conditions
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Silver(i) salts mediated stereospecific transformation of optically active propargylamines to axially chiral allenes with excellent enantioselectivities (17 examples with 96-99% ee; one substrate with 91% ee) without subsequent racemization.
- Lo, Vanessa Kar-Yan,Zhou, Cong-Ying,Wong, Man-Kin,Che, Chi-Ming
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supporting information; experimental part
p. 213 - 215
(2010/05/01)
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- Chromium-carbyne complexes: Intermediates for organic synthesis
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(Chemical Equation Presented) On the same route: Chromium-carbyne complexes are readily prepared by treatment of 1,1,1-trichloromethyl reagents with chromium(II) chloride. They serve as intermediates in the selective formation of a wide variety of products, such as alkynes, alkenes, β-hydroxy ketones, aldehydes, allylic alcohols, and allenes (see scheme, E = electrophile).
- Bejot, Romain,He, Anyu,Falck, John R.,Mioskowski, Charles
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p. 1719 - 1722
(2008/02/13)
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- The Polarized Absoption Spectrum of 1,3-Diphenyl-1,2-propadiene: Interaction between Mutually Perpendicular Equivalent ?-Electronic Systems
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The polarized UV absorption spectrum of 1,3-diphenyl-1,2-propadiene (DPA) wasx measured in a stretched polymer film at 101 K, and the polarization directions of the lectronic absorption bands were determined.Pariser-Parr-Pople (PPP) calculations extended
- Okubo, Jun,Shimazaki, Takayasu,Sato, Shin-ichi,Shinozaki, Hiraku
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p. 1405 - 1411
(2007/10/02)
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- Electron Demand in the Transition State of the Cyclopropylidene to Allene Ring Opening
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The electronic structure of the transition state for the cyclopropylidene to allene conversion has been probed.The methodology involved the relative rates of ring opening vs trapping by MeOH for a series of variously substituted 2,3-diarylcyclopropylidenes.With the assumption that the rate of trapping was unaffected by substituents, a Hammett correlation was constructed.The negative value (-0.72) for ρ indicated that the carbenic center attracts electron density in the ring-opening transition state, much like the cyclopropyl cation to allyl cation transition state.Temperature-dependent studies showed that the observed preference for ring opening was driven by entropy factors.Also, using reasonable estimates for the close to diffusion-controlled trapping activation enthalpies, the derived enthalpies for ring opening were in close agreement with the best theoretical values.
- Warner, Philip,Sutherland, Robert
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p. 6294 - 6300
(2007/10/02)
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- Allene Synthesis via Boron-stabilised Alkenyl Carbanions
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A new allene synthesis involving the boron-Wittig reaction of aldehydes with boron-stabilised carbanions is disclosed and its scope and limitations are explored.
- Pelter, Andrew,Smith, Keith,Jones, Kevin D.
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p. 747 - 748
(2007/10/02)
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