Homochiral methyl 4-aminopyrrolidine-2-carboxylates are readily obtained by means of asymmetric (3 + 2) cycloadditions between azomethine ylides and nitroalkenes, followed by catalytic hydrogenation of the intermediate 4-nitro cycloadducts. These 4-aminopyrrolidine-2-carboxylate esters belong to the L-series of natural amino acids and catalyze asymmetric Michael additions of ketones to nitroalkenes. However, the enantioselectivity observed with these novel unnatural organocatalysts is opposite to that obtained with L-proline. Since both 4-nitro and 4-amino L-proline esters are efficient organocatalysts of aldol reactions, these results permit to modulate asymmetric quimioselective aldol and conjugate addition reactions.

The first enantioselective 1,3-dipolar cycloaddition reaction of amino acid derived azomethine ylides and maleimides catalyzed by very stable and recyclable chiral (R)- or (S)-binap-AgClO(4) complexes is described. The reactions are performed at room temperature, in good yields, with high endo diastereoselectivity and enantioselectivity, the complex being recovered by simple filtration.

In this revision a summary of the trends of the formation of complex or not so complex heterocyclic structures through 1,3-DC of azomethine ylides is described. Diastereo-and enantioselective processes as well as nonasymmetric cycloadditions constitute very important synthetic tools for achieving all these series of compounds. The contents are classified as follows: 1. Introduction 2. Synthesis of spiroxindoles 3. Synthesis of spiropyrrolidines 4. Synthesis of spiropiperidines and piperidines 5. Synthesis of pyrrolidines and fused pyrrolidines 6. Synthesis of pyrrolizidines and indolizidines 7. Synthesis of quinolone and isoquinolines 8. Conclusions