Multicomponent assembly processes for the synthesis of diverse yohimbine and corynanthe alkaloid analogues.

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.