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.

A highly regio- and stereoselective synthesis of bispirooxindoles by 1,3-dipolar cycloaddition of in situ generated azomethine ylides from isatin and proline to different electron-deficient alkenes has been developed. The synthesis affords the desired bispiro scaffold compounds in excellent yields with high regioselectivity under mild conditions. The stereochemistry was determined by single-cry...

Phosphine-catalyzed [4+1] annulation of electron-deficient 1,3-dienes or 1,3-azadienes with maleimides has been successfully developed under very mild conditions, providing a convenient and highly efficient method for constructing 2-azaspiro[4.4]nonenes and 1,7-diazaspiro[4.4]nonenes. This reaction represents the first example of [4+1] cyclization between electron-deficient 4π-conjugated system...

A general preparation of new types of benzofurans, benzothiophenes and indoles is realized via chemoselective intramolecular Wittig reactions with the corresponding ester, thioester and amide functionalities using in situ formed phosphorus ylides as key intermediates. The reaction conditions are very mild, and numerous Michael acceptors and commercially available acid chlorides can be applied v...

A Rh2(OAc)4-catalyzed diazo decomposition reaction of diazo esters with 2-aminophenyl ketones is reported. A series of 3-hydroxy-2,2,3-trisubstituted indolines are produced in good yields with excellent diastereoselectivities via an intramolecular aldol-type trapping of ammonium ylides with ketone units.

Indolizidine and quinolizidine derivatives are readily assembled from proline or pipecolic acid and γ-nitroaldehydes by means of a decarboxylative annulation process. These reactions are promoted by simple acetic acid and involve azomethine ylides as reactive intermediates. The method was applied to the synthesis of an epiquinamide analog.

An efficient C-O, C-S and C-C bond-forming sequence leads to functionalised compounds bearing sulfur-substituted quaternary carbons. Ynamides are employed as diazo-equivalents to access the [2,3]-sigmatropic rearrangements of allyl sulfonium ylides by a three-component chemoselective oxidation and intermolecular ylide formation.

A series of novel dispirooxindoles have been synthesized through three-component 1,3-dipolar cycloaddition of azomethine ylides generated in situ by the decarboxylative condensation of isatin and an α-amino acid with the dipolarophile 5-benzylidene-1,3-dimethylpyrimidine-2,4,6-trione. This method has the advantages of mild reaction conditions, high atom economy, excellent yields, and high reg...

Acid treatment of densely substituted 2-silyl-1,2-dihydropyridines provides a new and convenient entry to reactive azomethine ylides that can (1) be protonated and reduced with high stereoselectivity to give piperidines, (2) participate in [3 + 2] dipolar cycloaddition to give tropanes, and (3) undergo a Nazarov-like 6-π electrocyclization that upon reduction give 2-azabicyclo[3.1.0] systems.

A regioselective efficient synthetic approach to N-imino-γ-carbolinium ylides via AgOTf-catalyzed iminoannulation has been developed. This transformation proceeds via a silver(i) triflate-catalyzed consecutive Friedel-Crafts reaction/N-C bond formation sequence between the readily available indole derivatives and propargylic alcohols.