17204-78-3

Upstream product

• 52577-34-1 (2-Ethyl-3,3-difluoro-4,4-dimethoxy-cyclobut-1-enyl)-benzene 
• 81144-22-1 3-Chlor-1-ethyl-3,4,4-trifluor-2-phenylcyclobuten 
• 81144-13-0 (3,4-Dioxo-2-phenylcyclobut-1-enyl)(methyl)malonsaeure-dimethylester 
• 5909-89-7 1-Aethyl-2-phenyl-3,3-dichlor-cyclobutenon 
• 622-76-4 1-phenyl-1-butyne 
• 711-78-4 3-methoxy-4-phenylcyclobutenedione 
• 13463-40-6 iron pentacarbonyl 
• 15321-51-4 diiron nonacarbonyl 

Downstream Products

• 81399-86-2 3-(5-Chlor-α-methyl-2-nitro-trans-styryl)-4-phenyl-3-cyclobuten-1,2-dion 
• 81758-50-1 3-(1-Bromethyl)-4-phenylcyclobuten-1,2-dion 
• 81287-11-8 3-(1-<(E)-Hydroxyimino>ethyl)-4-phenyl-3-cyclobuten-1,2-dion 
• 81287-09-4 2,4-Dihydroxy-2-methyl-5-phenyl-4-cyclopenten-1,3-dion 
• 81399-84-0 3-(4-Chlor-α-methyl-trans-styryl)-4-phenyl-3-cyclobuten-1,2-dion 
• 81399-82-8 3-(α-Methyl-4-nitro-trans-styryl)-4-phenyl-3-cyclobuten-1,2-dion 
• 81399-93-1 2-Acetoxy-2-<1-(3,4-dioxo-2-phenyl-1-cyclobuten-1-yl)ethyl>-1,3-indandion 
• 81399-81-7 trans-4-<2-(3,4-Dioxo-2-phenyl-1-cyclobuten-1-yl)-1-propenyl>benzonitril 
• 81758-70-5 S-<1-(3,4-Dioxo-2-phenylcyclobut-1-enyl)ethyl>-O-(ethyl)dithiocarbonat 
• 81758-66-9 S-<1-(3,4-Dioxo-2-phenyl-cyclobut-1-enyl)ethyl>thiobenzoat 
• 81758-57-8 <(3,4-Dioxo-2-phenylcyclobut-1-enyl)methylen>diacetat 
• 81758-71-6 <1-(3,4-Dioxo-2-phenylcyclobut-1-enyl)ethyl>-1-piperidincarbodithioat 
• 81758-63-6 4-Phenyl-3-(1-tosylethyl)cyclobuten-1,2-dion 
• 81758-72-7 <1-(3,4-Dioxo-2-phenylcyclobut-1-enyl)ethyl>-N-methyl-N-phenyldithiocarbamat 

Relevant academic research and scientific papers

A simple and convenient method for the synthesis of cyclobutenediones from alkynes using new Fe(CO)5/NaH/MeI reagent system

Iron carbonyl complexes prepared in situ using the Fe(CO)5/NaH/MeI reagent combination and alkynes at 25 °C give the corresponding cyclobutenediones in 50-65% yields after CuCl2 · 2H2O oxidation.

Reactive iron carbonyl reagents via reaction of metal alkoxides with Fe(CO)5 or Fe2(CO)9: Synthesis of cyclobutenediones via double carbonylation of alkynes

Alkoxy bases such as t-BuOK react with Fe(CO)5 to give reactive iron carbonyl intermediates that in turn react with alkynes at 70 °C in THF to give 1,2-cyclobutenediones in 70-93% yields after CuCl2· 2H2O oxidation. A novel 1,2-diacyloxyferrole derivative was isolated in the reaction of diphenylacetylene with Fe(CO)5/t-BuOK in the presence of acetyl chloride in contrast to the formation of a 1,4-diacyloxyferrole complex formed in the reaction using Fe(CO) 5/Me3NO. The Fe2(CO)9/t-BuOK reagent system also converts the alkynes to corresponding cyclobutenediones in 63-90% yields under similar reaction conditions.

Facile addition of dichloroketene to acetylenes mediated by zinc and ultrasound

The addition of dichloroketene, generated from trichloroacetyl chloride, zinc dust and ultrasound, to terminal and internal acetylenes is reported. This procedure is a more convenient alternative to Zn-Cu couple.

Reactions with Cyclobutenediones, LIX. - New Syntheses of 3-Alkyl-4-phenylcyclobutene-1,2-diones

The 3-alkyl-4-phenylcyclobutene-1,2-diones 4a-e have been prepared by degradation of the cyclobutene-1,2-diones 3a-e.The compounds 4a and 4b can also be obtained by hydrolysis of the cycloaddition products 5a and 5b.