- Synthesis of functionalized cyclopropylboronic esters based on a 1,2-metallate rearrangement of cyclopropenylboronate
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A procedure converting tribromocyclopropane to densely functionalized β-selenocyclopropylboronic ester using the 1,2-metallate rearrangement of a boron ate-complex has been developed. Treatment of an in situ-generated cyclopropenylboronic ester ate-complex with phenylselenenyl chloride triggered stereospecific rearrangement to produce functionalized cyclopropanes. DFT calculations for 1,2-metallate rearrangement suggested that the reaction proceeds through a seleniranium intermediate. This journal is
- Mizoguchi, Haruki,Seriu, Masaya,Sakakura, Akira
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Read Online
- Rapid access to cyclopentadiene derivatives through gold-catalyzed cycloisomerization of ynamides with cyclopropenes by preferential activation of alkenes over alkynes
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In this communication, gold-catalyzed intermolecular cycloisomerization of cyclopropenes and ynamides is investigated. The current transformation displayed an activation priority of double bonds over triple bonds by the cationic gold catalyst, giving the corresponding cyclopentadienes in good to excellent yields. Additionally, this protocol can be expanded to a one-pot two-step procedure for the synthesis of substituted cyclopentanones.
- Cheng, Xing,Zhu, Lei,Lin, Meijun,Chen, Jianxin,Huang, Xueliang
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p. 3745 - 3748
(2017/04/03)
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- Regioselective carbon-carbon bond cleavage in the oxidation of cyclopropenylcarbinols
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The strained double bond of cyclopropenylcarbinols undergoes a facile oxidation reaction to lead to unsaturated carbonyl derivatives. The distribution of the formed products depends on the relative stability of carbon-centered radical species, and the Sha
- Basheer, Ahmad,Mishima, Masaaki,Marek, Ilan
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supporting information; experimental part
p. 4076 - 4079
(2011/10/04)
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- Cyclopropenylcarbinol derivatives as new versatile intermediates in organic synthesis: Application to the formation of enantiomerically pure alkylidenecyclopropane derivatives
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The copper-catalyzed carbomagnesiation (or hydrometalation) reaction of chiral cyclopropenylcarbinol derivatives, obtained by means of a kinetic resolution of secondary allylic alcohols, leads to an easy and straightforward preparation of enantiomerically
- Simaan, Samah,Masarwa, Ahmad,Zohar, Elinor,Stanger, Amnon,Bertus, Philippe,Marek, Ilan
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scheme or table
p. 8449 - 8464
(2010/06/15)
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- Novel ene trimerization of 1-phenylcyclopropene
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1-Phenylcyclopropene (1) was synthesized by treatment of 1,1,2-tribromo-2-phenylcyclopropane (2) with 2.5 equiv of methyllithium followed by protonation. Compound 1 underwent ene dimerization to form ene dimer 5 followed by ene reaction with monomer 1 (enophile) to give an ene trimer 6. Both of these two ene reactions derived endo transition states. In the meantime, the [2+2] adduct, trans-1,2-diphenylbicyclo[3.1.0.02,4]hexane (7), was also formed. When the adduct 7 was heated at THF refluxing temperature, 1,2-diphenylcyclohexa-1,4-diene (8) was obtained. Compound 8 was treated with DDQ to yield o-diphenylbenzene.
- Lee, Gon-Ann,Chang, Chih-Yi
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p. 8949 - 8951
(2007/10/03)
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- gem-Dihalocyclopropane formation by iron/copper activation of tetrahalomethanes in the presence of nucleophilic olefins. Evidence for a carbene pathway
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The activation of CBr4 and CCl4 by a bimetallic iron/copper couple in acetonitrile is a new, inexpensive, nontoxic and efficient procedure for gem-dibromo- and gem-dichloromethylenation of nucleophilic alkenes. This new route to gem-dihalocyclopropanes involves dihalocarbene species.
- Léonel, Eric,Lejaye, Michael,Oudeyer, Sylvain,Paugam, Jean Paul,Nédélec, Jean-Yves
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p. 2635 - 2638
(2007/10/03)
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- Stable ethylene inhibiting compounds and methods for their preparation
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A method to inhibit the ethylene response in plants with cyclopropene compounds by first generating stable cyclopropane precursor compounds and then converting these compounds to the gaseous cyclopropene antagonist compound by use of a reducing or nucleophilic agent.
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- Novel tetramerization of 1-trimethylsilyl-2-phenylcyclopropene
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1-Trimethylsilyl-2-phenylcyclopropene (1) was generated from bromo- lithium exchange of 1-bromo-2-phenylcyclopropene followed by treatment with trimethylsilylchloride. Compound 1 underwent ene dimerizations to give endo and exo diners 5 and 6 which would dimerize by coupling reaction to yield a sole tetramer 4.
- Lee, Gon-Ann,Chang, Chih-Yi
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p. 3013 - 3016
(2007/10/03)
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- Formation of acetylenic acetals by ring opening of 1,1,2-trihalocyclopropanes under phase-transfer conditions
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A number of substituted 1,1-dibromo- and 1,1-dichlorocyclopropanes with an additional chlorine or bromine atom attached to C-2 were synthesized in reasonabk to good yields by dihalocarbene addition to the corresponding alkenes under phase-transfer conditions. When the trihalides were treated with 50% aqueous sodium hydroxide in the presence of ethanol. triethylbenzylammonium chloride and dichloromethane. most of the compounds underwent ring opening and afforded mixtures of acetylenic acetals, usually in good yields. The reaction most likely involves cyclopropene intermediates, which in some cases also rearrange to a minor extent to the corresponding vinylcarbenes and afford α,β-unsaturated aldehydes. Acta Chemica Scandinavica 1996.
- Sydnes, Leiv K.,Bakstad, Einar
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p. 446 - 453
(2007/10/03)
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