249730-06-1

Upstream product

• 123-73-9 trans-Crotonaldehyde 
• 542-92-7 cyclopenta-1,3-diene 
• 123-73-9 crotonaldehyde 

Relevant academic research and scientific papers

Organocatalysis using protonated 1,2-diamino-1,2-diphenylethane for asymmetric Diels-Alder reaction

Bisammonium salts of mono-N-alkylated chiral 1,2-diamino-1,2-diphenylethane (DPEN) were employed in the catalytic and asymmetric Diels-Alder reaction between cyclopentadiene and crotonaldehyde. The N-3-pentyl diamine·2HCl catalyst shows high endo/exo selectivity and endo-enantioselectivity for the cycloaddition, and this organocatalysis is the first example of the use of a chiral 1,2-diamine to generate an imine intermediate which is activated by an internal ammonium Br?nsted acid for the cycloaddition in a wet solvent.

Chiral Imidazolidin-4-one with catalytic amount of Dicationic ionic liquid act as a recoverable and reusable Organocatalyst for asymmetric Diels-Alder reaction

Imidazolidin-4-one is used as a recoverable organocatalyst for the asymmetric Diels-Alder reaction in the presence of catalytic amount of dicationic ionic liquid and trifluoroacetic acid as a co-catalyst. The Diels-Alder reaction between model substrate cyclopentadiene and crotonaldehyde gave the product in 95% conversion and 87% ee of the endo-product. The catalyst was shown better reusability when the 20?mol% of dicationic ionic liquid was used and catalyst was reused upto 5 cycles, conversion remains upto 3 recycles but ee of endo-9 was slightly droped.

Synthesis of MacMillan catalyst modified with ionic liquid as a recoverable catalyst for asymmetric Diels-Alder reaction

MacMillan catalyst was modified with imidazolium ionic liquid by ester linkage and acts as recoverable and reusable catalyst for asymmetric Diels-Alder reactions. A Diels-Alder reaction between cyclopentadiene and crotonaldehyde was carried out using MacMillan catalyst modified with ionic liquid (5 mol%) using trifluoroacetic acid (5 mol%) as co-catalyst in acetonitrile-water (95 : 5) at room temperature, to give 94% conversion of Diels-Alder adduct with exo/endo (1 : 1.1) and 90% ee of endo product. The catalyst was recovered and reused up to 5 cycles with a slight decrease in ee and product conversion.

Novel tetrahydroisoquinoline based organocatalysts for asymmetric Diels-Alder reactions: Insight into the catalytic mode using ROESY NMR and DFT studies

For the first time an organocatalyst bearing a secondary nitrogen within a cyclohexane ring has been evaluated in the asymmetric Diels-Alder reaction. This organocatalyst is also the first of its kind based on a (1R,3S)-6,7-dimethoxy- 1-phenyl-1,2,3,4-tetrahydroisoquinoline backbone. These catalysts were tested over a range of dienes and dienophiles and displayed promising chemical conversions of up to 100% with up to 64% ee with triflic acid as the cocatalyst. Density functional theory computational studies and 2D NMR spectroscopy were used to determine the structure of the intermediate iminium ion formed between the most efficient catalyst and cinnamaldehyde. The reaction profile for each of the four possibilities in this reaction were calculated and it was found that the iminium intermediate leading to the major product is higher in energy but kinetically preferred. The activation energies of all possible reaction paths were calculated and the results correlated with the observed products. These experiments revealed that the presence of both (E)- and (Z)-isomers of the cinnamaldehyde were contributing factors for the low enantioselectivity of the reaction products.

Enantioselective Diels-Alder reactions of enals: Fighting species multiplicity of the catalyst with donor solvents

Chiral Lewis acids obtained from reactions of N-arylsulphonylamino acids with borane adducts effectively catalyze Diels-Alder additions of α,β-unsaturated aldehydes. Maximum enantioselectivity (methacrylaldehyde: 86 %ee, crotonaldehyde: 81 %ee) was achieved in donor solvents. The first results with new chiral Lewis acids derived from C2-symmetric N-sulphonyl derivatives of 2,2'-diamino-1,1'-binaphthyl are also presented.