4258-40-6

Upstream product

• 32776-15-1 1,5-diphenylpentane-1,4-dione 
• 50790-27-7 2,2-diphenyl-4-pentenoyl chloride 
• 35225-79-7 dibenzylideneacetone 
• 74-85-1 ethene 
• 201230-82-2 carbon monoxide 
• 501-65-5 diphenyl acetylene 
• 925-90-6 ethylmagnesium bromide 
• 38854-88-5 5-Hydroxy-2,3-diphenyl-cyclopent-2-enon 
• 10034-85-2 hydrogen iodide 
• 64-19-7 acetic acid 
• 16661-10-2 5-chloro-2,3-diphenyl-cyclopent-2-enone 
• 30126-74-0 1,2-diphenylcyclopent-2-en-1-ol 
• 321155-39-9 dimethyl(2-pyridinyl)(vinyl)silane 
• 107-02-8 acrolein 

Downstream Products

• 26288-86-8 4-Hydroxy-5-oxo-4,5-diphenyl-pentansaeure 
• 7433-53-6 cis-1,2-diphenylcylopentane 
• 1187791-61-2 5-bromo-2,3-diphenylcyclopent-2-en-1-one 

Relevant academic research and scientific papers

Unusual Nazarov cyclization in near-critical water

The Nazarov reaction of trans,trans-dibenzylidene acetone in near-critical water with or without additional carbon dioxide produces 2,3-diphenyl-2- cyclopentenone instead of the conventional Nazarov product, 3,4-disubstituted 2-cyclopentenone. The use of

Synthesis of Cyclopentenones with Reverse Pauson-Khand Regiocontrol via Ni-Catalyzed C-C Activation of Cyclopropanone

A formal [3 + 2] cycloaddition between cyclopropanone and alkynes via Ni-catalyzed C-C bond activation has been developed, where 1-sulfonylcyclopropanols are employed as key precursors of cyclopropanone in the presence of trimethylaluminum. The transformation provides access to 2,3-disubstituted cyclopentenones with complete regiocontrol, favoring reverse Pauson-Khand products, where the large substituent is located at the 3-position of the ring. In the process, the trimethylaluminum additive is thought to play multiple roles, including as a Br?nsted base triggering the equilibration to cyclopropanone and liberation of methane, as well as a source of Lewis acid to activate the carbonyl group toward Ni-catalyzed C-C activation.

Iodine-Catalyzed Iso-Nazarov Cyclization of Conjugated Dienals for the Synthesis of 2-Cyclopentenones

Molecular iodine was identified as an efficient catalyst for the cycloisomerization of conjugated dienals to substituted 2-cyclopentenones. DFT calculations suggested an unexpected concerted character for this cyclization.

Ruthenium- and Rhodium-Catalyzed Ring-Opening Coupling Reactions of Cyclopropenones with Alkenes or Alkynes

Ru 3 (CO) 12 -catalyzed divergent ring-opening coupling reactions of a cyclopropenone with methyl acrylate (an electron-deficient alkene) are developed. Under an argon atmosphere, a decarbonylative linear codimer is obtained, while cyclopentenones are obtained under carbon monoxide (20 atm) without decarbonylation. While ruthenium complexes show no catalytic activity for the ring-opening cocyclization of cyclopropenones with ethylene (20 atm) or bicyclo[2.2.1]hept-2-ene (2-norbornene), rhodium complexes, especially [RhCl(η 4 -1,5-cod)] 2, show high catalytic activity for the desired cocyclization reactions to give the corresponding cyclopentenones in high yields and selectivities. In addition, [RhCl(η 4 -1,5-cod)] 2 realizes the catalytic ring-opening cocyclization of cyclopropenones with internal alkynes to give the corresponding cyclopentadienones. In all these reactions, ruthena- or rhodacyclobutenones are considered to be key intermediates, generated by strain-driven oxidative addition of a cyclopropenone C-C bond to an active ruthenium or rhodium species.

Rh-catalyzed reagent-free ring expansion of cyclobutenones and benzocyclobutenones

Here we report a reagent-free rhodium-catalyzed ring-expansion reaction via C-C cleavage of cyclobutenones. A variety of poly-substituted cyclopentenones and 1-indanones can be synthesized from simple cyclobutenones and benzocyclobutenones. The reaction condition is near pH neutral without additional oxidants or reductants. The potential for developing a dynamic kinetic asymmetric transformation of this reaction has also been demonstrated. Further study supports the proposed pathway involving Rh-insertion into the cyclobutenone C-C bond, followed by β-hydrogen elimination, olefin insertion and reductive elimination.

Polymer-mediated reactions. A Nazarov-like cyclization

The polymer PEDOT+ mediates a Nazarov-like cyclization of dienones, in an heterogeneous system and in hydrocarbon solvents. The polymer-mediated reactions show clear differences in product formation when compared to the same reaction with tosic acid, or when compared to reports in the literature. Comparable or improved yields are observed, as well as the ability to give a -Nazarov product in cases where treatment with acid fails to give cyclization, or leads to an undesirable rearrangement. In addition, the ability to recycle the polymer makes this a potentially useful protocol for an important organic chemical reaction. Georg Thieme Verlag Stuttgart · New York.

CuCl-catalyzed reaction of zirconacyclopentenes with oxalyl chloride: a new pathway for the preparation of cyclopentenones

Zirconacyclopentenes, which are easily prepared from alkynes and EtMgBr (or ethylene) and Cp2ZrCl2, reacted with oxalyl chloride in the presence of catalytic amount of CuCl to give cyclopentenones in high yields. The reaction was per

A Pd(II)-catalyzed ring-expansion reaction of cyclic 2-azidoalcohol derivatives: Synthesis of azaheterocycles

(Chemical Equation Presented) A Pd(II)-catalyzed ring expansion-reaction of cyclic 2-azidoalcohol derivatives was found to proceed via an unprecedented C-C bond cleavage-C-N bond formation sequence, providing substituted azaheterocycles.

A Pauson-Khand-type reaction between alkynes and olefinic aldehydes catalyzed by rhodium/cobalt heterobimetallic nanoparticles: An olefinic aldehyde as an olefin and CO source

Co/Rh (Co:Rh = 2:2) heterobimetallic nanoparticles derived from Co 2Rh2(CO)12 react with alkynes and α,β-unsaturated aldehydes such as acrolein, crotonaldehyde, and cinnamic aldehyde and release products resulting from [2 + 2 + 1]cycloaddition of alkyne, carbon monoxide, and alkene. α,β-Unsaturated aldehydes act as a CO and alkene source. These reactions produce 2-substituted cyclopentenones.