@article{oai:soar-ir.repo.nii.ac.jp:00012488,
 author = {Suga,  Hiroyuki and Arikawa,  Tadashi and Itoh,  Kennosuke and Okumura,  Yukihisa and Kakehi,  Akikazu and Shiro,  Motoo},
 issue = {7},
 journal = {HETEROCYCLES},
 month = {Jul},
 note = {1,3-Dipolar cycloadditions between acrolein and various N,N'-cyclic azomethine imines in the presence of L-proline and its derivatives as organocatalysts were investigated. Reactions that were catalyzed by (S)-indline-2-carboxylic acid (30 mol%) in CHCl3/MeOH 97:3 (v/v) showed high exo-selectivities (exolendo 91:9 similar to 99:1) and enantioselectivities (75 similar to 98% ee). In contrast, reactions catalyzed by L-proline (30 mol%) under similar conditions favored the endo-cycloadduct (83:27 similar to 99:1) with modest to good enantioselectivities (31 similar to 83% ee). Based on our studies, the diastereoselective mechanism of the L-proline-catalyzed reaction was found to involve the isomerization of the exo- to the endo-cycloadduct in the presence of L-proline., Article, HETEROCYCLES. 81(7):1669-1688 (2010)},
 pages = {1669--1688},
 title = {ASYMMETRIC 1,3-DIPOLAR CYCLOADDITION REACTIONS OF AZOMETHINE IMINES WITH ACROLEIN CATALYZED BY L-PROLINE AND ITS DERIVATIVES},
 volume = {81},
 year = {2010}
}