249730-06-1Relevant articles and documents
Organocatalysis using protonated 1,2-diamino-1,2-diphenylethane for asymmetric Diels-Alder reaction
Kim, Kyoung Hoon,Lee, Seil,Lee, Dae-Woong,Ko, Dong-Hyun,Ha, Deok-Chan
, p. 5991 - 5994 (2005)
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.
Synthesis of MacMillan catalyst modified with ionic liquid as a recoverable catalyst for asymmetric Diels-Alder reaction
Chauhan, ManMohan Singh,Kumar, Pramod,Singh, Surendra
, p. 52636 - 52641 (2015/06/25)
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.
Enantioselective Diels-Alder reactions of enals: Fighting species multiplicity of the catalyst with donor solvents
Sartor,Saffrich,Helmchen,Richards,Lambert
, p. 639 - 642 (2007/10/02)
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.