Asymmetric 1,3-Dipolar Cycloadditions of Cyclic Stabilized Ylides Derived from Chiral 1,2-Amino Alcohols

Asymmetric 1,3-dipolar cycloadditons of stabilized azomethine ylides with nitroalkenes.

This review highlights the biological importance of many polysubstituted nitro-prolines and -pyrrolidines. Their preparation using asymmetric 1,3-dipolar cycloadditions of azomethine ylides with nitroalkenes using diastereoselective and enantioselective strategies is described remarking the scope and main features of each one.

Diastereoselective 1,3-dipolar cycloaddition of pyrylium ylides with chiral enamides.

Chiral enamides 5f-i were found to react with pyrylium ylides to give cycloadducts 6d-i in good yields with an excellent level of stereoselectivity. The chiral auxiliary was successfully removed on hydrogenolysis of compound 6f in continuous flow (H-Cube) resulting in the first asymmetric synthesis of complex amine 8.

Metal Complexes versus Organocatalysts in Asymmetric 1,3-Dipolar Cycloadditions

Regioselectivie Synthesis of New Spiro-Oxindolopyrrolidines via a Three-Component Asymmetric 1,3-Dipolar Cycloaddition Reaction of Azomethine Ylides aAnd Chiral Menthyl Cinnamate

An efficient, one-pot, four-component procedure for the synthesis of a small library of new chiral spiro- oxindolopyrrolidines with high regio-, diastereo- (>99:1 dr), and enantioselectivity (up to 80% ee) is described. In this process, the regio- and stereochemical 1,3-dipolar cycloaddition of azomethine ylides, which were generated insitu by the reaction of isatin derivatives and sarcosin,wit...

Photogeneration and Thermogeneration of Carbonyl Ylides: 1,3-dipolar Cycloadditions of 2,3-diaryloxiranes to Dipolarophiles*

A series of symmetrically substituted 2,3-diaryloxiranes 1 4 (Fig. 1) has been studied as photoprecursors for carbonyl ylides [l 31. The stereochemistry of the adducts obtained on the interception of these 4rzn transient system with a variety of dipolarophiles provides information on the mode(s) of electrocyclic opening of the oxiranes to carbonyl ylides as well as on the mechanism of the 4n + ...