39133-58-9

Upstream product

• 104-88-1 4-chlorobenzaldehyde 
• 78-80-8 2-methylbut-1-en-3-yne 

Downstream Products

• 1385018-06-3 (E)-5-(4-chlorobenzylidene)-2-methyl-4-oxocyclopent-1-en-1-yl acetate 
• 1385018-24-5 (Z)-5-(4-chlorobenzylidene)-2-methyl-4-oxocyclopent-1-en-1-yl acetate 
• 1385017-88-8 1-(4-chlorophenyl)-4-methylpent-4-en-2-yn-1-yl acetate 

Relevant academic research and scientific papers

Gold(I)-Catalyzed Tandem Cycloisomerization and Fluorination of 1,3(4)-Enyne Esters with NFSI: One-Pot Assembly of 5-Fluoro- Cyclopentenones

An efficient synthetic approach for the synthesis of 5-fluoro-cyclopentenones containing a fluorine-substituted carbon stereocenter that relies on gold(I)-catalyzed cycloisomerization and fluorination sequence of 1,3(4)-enyne esters with N-fluorbenzensulfonimide (NFSI) is described. This tandem transformation exhibited a broad substrate scope and excellent functional group compatibility, providing a novel protocol for rapid assembly 5-fluoro-cyclopentenones in good to excellent yields under mild reaction conditions. The mechanistic studies revealed that the transformation involves a gold-catalyzed cycloisomerization and electrophilic fluorination cascade to give the 5-fluoro-cyclopentenones. (Figure presented.).

Catalytic asymmetric enyne addition to aldehdyes and Rh(I)-catalyzed stereoselective domino Pauson-Khand/[4 + 2] cycloaddition

The 1,1′-bi-2-naphthol-ZnEt2-Ti(OiPr) 4-Cy2NH system is found to catalyze the 1,3-enyne addition to aliphatic aldehydes as well as other aldehydes at room temperature with 75-96% yield and 82-97% ee. This system is also broadly applicable for the highly enantioselective reaction of other alkyl-, aryl-, and silylalkynes with structurally diverse aldehydes. The propargylic alcohols prepared from the catalytic asymmetric enyne addition to aliphatic aldehydes are used to prepare a series of optically active trienynes. In the presence of a catalytic amount of [RhCl(CO)2]2 and 1 atm of CO, the optically active trienynes undergo highly stereoselective domino Pauson-Khand/[4 + 2] cycloaddition to generate optically active multicyclic products. The Rh(I) catalyst is also found to catalyze the coupling of a diyne with CO followed by [4 + 2] cycloaddition to generate an optically active multicyclic product. These transformations are potentially useful for the asymmetric synthesis of polyquinanes containing a quaternary chiral carbon center.

Diastereoselective [4 + 1] Cycloaddition of Alkenyl Propargyl Acetates with CO Catalyzed by [RhCl(CO)2]2

A class of alkenyl propargyl acetates, RCH(OAc)C≡CC(CH 3)=CH2 (5), are found to undergo [4 + 1] cycloaddition with CO (1 atm) in the presence of [RhCl(CO)2]2 in refluxing 1,2-dichloroethane to give cyclopentenones (6) in good yields. It has been demonstrated that, when the R group of 5 is a phenyl group bearing o-electron-withdrawing substituents, up to 10:1 diastereoselectivity and 96% yield can be achieved for the [4 + 1] cycloaddition. This process provides a convenient method to construct highly functionalized cyclopentenones that are useful in organic synthesis.