1,3-Dipole-based nitrogen containing carbanion, particularly azomethine ylide, is widely used in cycloaddition reactions. It has important and widespread application not only limited in the synthesis of core structural motifs like pyrrolidine and spiropyrrolidines but also in stereocontrolled dipolarophile for building important classes of heterocyclic compounds. Herein, we will explore the current development of azomethine ylide and all the possible applications of this small but elegant fragment using a green approach. This review article will also covers the application of this super energetic, pharmaceutically important moiety in the field of asymmetric, organocatalytic, and transition metal-catalyzed synthesis processes coupled with a theoretical approach. The development of an environmentally safe multicomponent, tandem synthesis method mediated by azomethine ylide will be discussed in detail in this current review article, which will be important for researchers in the field of organic synthesis, heterocyclic chemistry, and medicinal chemistry.

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Propellanes are polycyclic compounds in which tricyclic systems share one carbon-carbon single bond. Propellane frameworks that consist of larger sized rings are found in a variety of natural products. As an approach to the stereoselective synthesis of the propellane framework, one of the efficient methods is forming several rings in a single operation. Lapidilectine B ( 1 ) is composed of a propellane framework and was synthesized through the oxidative cyclization of trisubstituted alkenes. When the alkene with an ester moiety was treated with N -iodosuccinimide (NIS), iodocyclization proceeded to give the cyclic carbamate. On the other hand, when PhI(OAc) 2 was allowed to react in the carboxyl form, a furoindolin-2-one structure corresponding to the A-B-C ring of lapidilectine B ( 1 ) was produced. Furthermore, when Pd(OAc) 2 catalyst was used for cyclization under oxidative conditions, the product yield was improved.

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The total synthesis of Kopsia lapidilecta alkaloid (+/-)-lapidilectine B is described. Notable elements of this synthesis include the first natural products application of the Smalley azido-enolate cyclization to form the 1,2-dihydro-3H-indol-3-one (indoxyl) core and installation of the pyrrolidine ring by a 2-azaallyllithium [3+2] cycloaddition with the acetylene equivalent phenyl vinyl sulfide. Closure of the eight-membered perhydroazocine ring is accomplished via the intramolecular S(N)2 substitution of a mesylate. This constitutes the first synthesis of a member of the 5,6,12,13-tetrahydro-11a,13a-ethano-3H-pyrrolo[1',2':1,8]azocino[5,4-b]indole class of alkaloids.

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