164171-78-2

Upstream product

• 164171-80-6 1-(4-methoxyphenyl)cyclobutan-1-ol 
• 75-89-8 2,2,2-trifluoroethanol 
• 104-92-7 1-bromo-4-methoxy-benzene 
• 1191-95-3 cyclobutanone 
• 55088-84-1 4-methoxybenzylidenecyclopropane 
• 696-62-8 para-iodoanisole 
• 101391-44-0 1-bromobicyclo<1.1.0>butane 
• 215038-69-0 1-(4-methoxyphenyl)cyclobutyl acetate 
• 67-56-1 methanol 

Downstream Products

• 34603-55-9 1-(4-methoxyphenyl)cyclopropane-1-carbaldehyde 
• 768-60-5 4-methoxyphenylacetylen 

Relevant academic research and scientific papers

Oxidative Ring Contraction of Cyclobutenes: General Approach to Cyclopropylketones including Mechanistic Insights

An original oxidative ring contraction of easily accessible cyclobutene derivatives for the selective formation of cyclopropylketones (CPKs) under atmospheric conditions is reported. Comprehensive mechanistic studies are proposed to support this novel, yet unusual, rearrangement. Insights into the mechanism ultimately led to simplification and generalization of the ring contraction of cyclobutenes using mCPBA as an oxidant. This unique and functional group tolerant transformation proceeds under mild conditions at room temperature, providing access to a new library of polyfunctionalized motifs. With CPKs being attractive and privileged pharmacophores, the elaboration of such a simple and straightforward strategy represents a highly valuable tool for drug discovery and medicinal chemistry. Additionally, the described method was employed to generate a pool of bioactive substances and key precursors in a minimum number of steps.

A one-pot preparation of aryl- and heteroarylcycloalkenes: Application to the total synthesis of (±)-laurokamurene B

A general one-pot method has been developed for the preparation of various aryl- and heteroarylcycloalkenes. After lithiation of aryl and heteroaryl bromides followed by transmetalation with CeCl3, the organocerium addition to cycloalkanones proceeds clea

Palladium-catalyzed ring enlargement of aryl-substituted methylenecyclopropanes to cyclobutenes

Methylenecyclopropanes 1 could be converted to the corresponding cyclobutenes 2 under the catalysis of palladium acetate in the presence of metal bromide in 1,2-dichloroethane under mild conditions. A plausible reaction mechanism has been proposed on the

An efficient synthesis of arylcyclobutenes via cross-coupling of aryl halides with 1-(Tri-n-butylstannyl)cyclobutene

1-Tri-n-butylstannylcyclobutene, obtained from 1-bromocyclobutene by lithium/bromine exchange and transmetalation with chloro-tri-n-butylstannane, could be effectively converted with aryl halides into 1-arylcyclobutenes by the Stille cross-coupling proced

Preparation of aryl cyclobutenes under mild and neutral conditions

Aryl cyclobutyl acetates were converted to the corresponding aryl cyclobutenes with lithium bromide in good yields (50-97%) and in high purity.

Laser flash photolysis study of arylcyclopropylcarbenium ions: Cation stabilizing abilities of cyclopropyl and phenyl groups

Arylcyclopropylcarbenium ions, Ar(c-Pr)CH+, were generated as transient intermediates by laser flash photolysis (LFP) of trans-2,3-diphenylaziridinimines of aryl cyclopropyl ketones in 2,2,2-trifluoroethanol (TFE). The carbocations are thought to arise by way of diazo compounds and carbenes. Rate constants for the unimolecular decay in TFE and for the bimolecular reaction with methanol in TFE were obtained for Ar(c-Pr)CH+ and for analogous arylphenylcarbenium ions, ArPhCH+. Within these series, the cation stabilizing abilities of cyclopropyl and phenyl groups are found to be similar in magnitude. However, cyclopropyl responds more strongly than phenyl to increasing electron demand. Hence cyclopropyl is superior to phenyl in cation stabilizing ability for Ar = Ph but inferior to phenyl for Ar = 4-MeOC6H4.

Cyclobutene photochemistry. Substituent effects on the photochemistry of 1-phenylcyclobutene

The photochemistry and photophysic of 1-phenylcyclobutene and five aryl-substituted derivatives have been studied in various solvents at room temperature.All six compounds fluoresce with quantum yields in the 0.2-0.3 range in cyclohexane and acetonitrile solution. 1-Phenylcyclobutene undergoes -cycloreversion (γ = 0.09) to yield phenylacetylene upon photolysis in either hydrocarbon or acetonitrile solution, and undergoes (Markovnikov) solvent addition upon irradiation in methanol solution (γ = 0.08) in addition to cycloreversion.Triplet sensitization and quenching experiments indicate that cycloreversion and methanol addition are both excited singlet state processes.None of the six compounds studied undergo ring opening to the corresponding 2-aryl-1,3-butadiene in detectable yield.Quantum yields for cycloreversion in cyclohexane, acetonitrile, and methanol solution and methanol addition have been determined for the six compounds, along with excited singlet state lifetimes.The quantum yields and rate constants for cycloreversion and methanol addition are both enhanced by substitution with electron-donating groups.The variation in the rate constant for cycloreversion with substituent indicates that there is substantial dipolar character developed in the cyclobutenyl ?-bond framework during the reaction, in almost exact correspondence with that developed in the ? system during photoprotonation.No deuterium scrambling is observed in 1-phenylcyclobutene-2,4,4-d3 after photolysis in pentane solution to ca. 80percent conversion, indicating that sleletal rearrangements leading to cyclopropyl carbenes do not occur in the direct photolysis of arylcyclobutene derivatives.A pericyclic mechanism for the photocycloreversion reaction is suggested.Triplet-triplet absorption spectra and triplet lifetimes of 1-phenyl-, 1-(para-methylphenyl)-, and 1-(para-trifluoromethylphenyl)cyclobutene in hydrocarbon solution are also reported. Key words: photochemistry, cyclobutene, fluorescence, -cycloreversion, substituent effects, nanosecond laser flash photolysis, lifetime, triplet state, styrene, photoaddition