3409-37-8

Upstream product

• 69849-23-6 2-phenyl-2-<(trimethylsilyl)oxy>-4-hexen-3-one 
• 591-51-5 phenyllithium 
• 78012-31-4 (1S,4R)-3-Benzenesulfonyl-4-methyl-cyclopent-2-enol 
• 185309-06-2 3-methyl-5-phenyl-4-pentynal 
• 536-74-3 phenylacetylene 
• 123-73-9 crotonaldehyde 
• 98-01-1 furfural 
• 53701-48-7 (2E,4E)-3-methyl-5-phenylpenta-2,4-dienal 
• 634603-25-1 2-(1-methyl-3-oxo-3-phenyl-propyl)-malonic acid diethyl ester 
• 98-86-2 acetophenone 
• 60907-91-7 2-furyl(phenyl)methanol 
• 141-32-2 acrylic acid n-butyl ester 
• 70214-59-4 5-phenylpent-4-ynal 
• 2680-03-7 N,N-Dimethylacrylamide 

Relevant academic research and scientific papers

Rhodium-catalyzed regio-, diastereo-, and enantioselective intermolecular [4+2] carbocyclization of 4-alkynals with electron-deficient alkenes

We established that a cationic rhodium(I)/dppf or dppb complex catalyzes a regio- and diastereoselective intermolecular [4+2] carbocyclization of 5-trimethylsilyl-4-pentynals with electron-deficient alkenes leading to cyclohexanones. We also established that a cationic rhodium(I)/(R,R)-Warphos complex catalyzes a regio- and enantioselective intermolecular [4+2] carbocyclization of 5-substituted 4-pentynals and 2-alkynylbenzaldehydes with N,N-dialkylacrylamides leading to enantio-enriched cyclohexanones and tetralones, respectively. A single olefin isomer was produced in every carbocyclization. Regioselectivities of the alkene insertion depend on the alkenes used. Mechanistic study suggested that a key intermediate in this intermolecular [4+2] carbocyclization is a five-membered acylrhodium intermediate, formed by cis addition of the rhodium hydride to the metal-bound alkyne. This method serves as an attractive new route to highly functionalized cyclohexanones in view of the one-step access to 5-substituted 4-pentynals and 2-alkynylbenzaldehydes starting from readily available terminal alkynes. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.

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.

Mg-promoted facile and selective intramolecular cyclization of aromatic δ-ketoesters

Treatment of various types of aromatic δ-ketoesters 2, 7, and 9 with Mg-turnings for Grignard reaction at -5 to 0 °C in N,N-dimethylformamide (DMF) containing trimethylsilyl chloride (TMSCl) brought about selective and reductive intramolecular cyclization

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.

Regioselective synthesis of trisubstituted cyclopentadienyl ligands from furans

1,2,3- And 1,2,4-trisubstituted cyclopentadienyl manganese tricarbonyl compounds have been synthesized regioselectively from furans following a common synthetic strategy. The key steps include the transformation of furylcarbinols into hydroxycyclopentenones followed by the conjugate addition of Grignard reagents under chelation directed conditions. This affords hydroxycyclopentanones which can be dehydrated to cyclopentenones. These compounds are further elaborated into the final targets by the 1,2-addition of organolithium reagents.

Enantioselective synthesis of cyclopentenones via rhodium-catalyzed kinetic resolution and desymmetrization of 4-alkynals

We have developed two new catalytic processes that provide efficient access to interesting chiral building blocks, cyclopentenones that bear tertiary and quaternary stereocenters, in high enantiomeric excess and very good yield. Structures such as these h

Three-Carbon Annelations. Regiocontrolled Reactivity of Trimethylsilyl- and Ethoxyethyl-Protected Cyanohydrins. Versatile Homoenolate and Acyl Anion Equivalents

The trimethylsilyl- (2) and ethoxyethyl- (4) protected cyanohydrins of α,β-unsaturated aldehydes are utilized as three-carbon annelation reagents.Metalated reagent 2 displays exclusive α reactivity with aldehydes and ketones at -78 deg C.Metalated reagent 4 displays exclusive α reactivity at -78 deg C and exclusive γ reactivity at 0 deg C.Reagent 4 thus allows for complete regiocontrol in its addition to aldehydes and ketones which permits selective addition of either a homoenolate or an acyl anion equivalent.Metalation of the α product 11 at -78 deg C with subsequent warming to 0 deg C produces exclusively the γ product, confirming the reversible nature of the addition to the carbonyl.The derived α '-trimethylsiloxy enones 17 (R3=Me3Si), α '-hydroxy enones 17 (R3=H), α '-acetoxyenones 17 (R3=Ac), and γ-lactones 10 are useful cyclopentenone precursors.Treatment of 17 with p-TsOH in toluene at reflux produces cyclopentenones.The reaction proceeds via the postulated intermediacy of a pentadienyl cation 15 which undergoes in situ electrocyclic ring closure.