73301-20-9Relevant academic research and scientific papers
Unsaturated aldehydes as alkene equivalents in the Diels-Alder reaction
Taarning, Esben,Madsen, Robert
supporting information; experimental part, p. 5638 - 5644 (2009/05/30)
A one-pot procedure is described for using α,β-unsaturated aldehydes as olefin equivalents in the Diels-Alder reaction. The method combines the normal electron demand cycloaddition with aldehyde dienophiles and the rhodium-catalyzed decarbonylation of aldehydes to afford cyclohexenes with no electron-with-drawing substituents. In this way, the aldehyde group serves as a traceless control element to direct the cycloaddition reaction. The Diels-Alder reactions are performed in a diglyme solution in the presence of a catalytic amount of boron trifluoride etherate. Subsequent quenching of the Lewis acid, addition of 0.3% of [Rh(dppp)2Cl] and heating to reflux achieves the ensuing decarbonylation to afford the product cyclohexenes. Under these conditions, acrolein, crotonaldehyde and cinnamaldehyde have been reacted with a variety of 1,3-dienes to afford cyclohexenes in overall yields between 53 and 88%. In these transformations, the three aldehydes serve as equivalents of ethylene, propylene and styrene, respectively.
REGIOSELECTIVE DIELS-ALDER REACTIONS. THE NITRO GROUP AS A REGIOCHEMICAL CONTROL ELEMENT
Ono, Noboru,Miyake, Hideyoshi,Kamimura, Akio,Kaji, Aritsune
, p. 1929 - 1936 (2007/10/02)
The sequence of the Diels-Alder reaction of α-nitroalkenes with diens and subsequent denitration with Bu3SnH provides a new method for the regioselective construction of cyclohexene derivatives.
Dienophilic Properties of Phenyl Vinyl Sulfone and trans-1-(Phenylsulfonyl)-2-(trimethylsilyl)ethylene. Their Utilization as Synthons for Ethylene, 1-Alkenes, Acetylene, and Monosubstituted Alkynes in the Construction of Functionalized Six-Membered Rings via ? Cycloaddition Meth.
Carr, Richard V. C.,Williams, Richard V.,Paquette, Leo A.
, p. 4976 - 4986 (2007/10/02)
Useful procedures for effecting the indirect capture of ethylene, acetylene, 1-alkenes, and monosubstituted alkynes in Diels-Alder cycloadditions have been developed.In the first sequence, phenyl vinyl sulfone is shown to enter into ? reactions as a moderately reactive dienophile and to do so with very good regioselectivity.The resulting adducts can be directly desulfonated or alkylated prior to such reduction.A wide range of functional groups can be appended in this fashion at a specific locus within the newly formed six-membered ring.When the analogous chemistry is applied to trans-1-(phenylsulfonyl)-2-(trimethylsilyl)ethylene (2), adducts result which undergo ready fluoride ion induced elimination with efficient introduction of a double bond.The use of 2 and its d2 derivative is highlighted by the synthesis of several functionalized dibenzobarrelenes.
