[reaction: see text] A diastereoselective total synthesis of securinine in optically pure form was achieved by employing ring-closing metathesis of the corresponding dienyne compound as a key step.

Several novel multicomponent assembly processes have been developed for the rapid and efficient assembly of various heterocyclic scaffolds bearing a tetrahydroisoquinoline core, each of which allows for facile derivatization to access a diverse array of compounds. This work led to the serendipitous discovery of a new method for the synthesis of a fused quinazolone ring system, which was applied to a one-step total synthesis of the quinazolinocarboline alkaloid rutaecarpine.

The synthesis of 2-aminobenzenesulfonamide-containing cyclononyne (ABSACN), starting from 2-nitrobenzenesulfonamide and but-2-yne-1,4-diol via Mitsunobu and Nicholas reactions, is described for the development of an adjustable alkyne reagent in click reactions. In a strain-promoted azide-alkyne cycloaddition (SPAAC) reaction, the reactivity of the alkyne is controlled by introducing various N-functionalities. The structure-reactivity relationship is found to be influenced by a transannular hydrogen bond between amino and sulfonyl groups.

A strategy involving a Mannich-type multicomponent assembly process followed by a 1,3-dipolar cycloaddition has been developed for the rapid and efficient construction of parent heterocyclic scaffolds bearing indole and isoxazolidine rings. These key intermediates were then readily elaborated using well-established protocols for refunctionalization and cross-coupling to access a diverse 180-member library of novel pentacyclic and tetracyclic compounds related to the Yohimbine and Corynanthe alkaloids. Several other new multicomponent assembly processes were developed to access dihydro-β-carboline-fused benzodiazepines, pyrimidinediones, and rutaecarpine derivatives.