An oxidative amidation and heterocyclization approach for the synthesis of β-carbolines and dihydroeudistomin Y

Abstract

SummaryA novel synthetic methodology has been developed for the synthesis of dihydro-β-carboline derivatives employing oxidative amidation–Bischler–Napieralski reaction conditions using tryptamine and 2,2-dibromo-1-phenylethanone as key starting materials. A number of dihydro-β-carboline derivatives have been synthesized in moderate to good yields using this methodology. Attempts were made towards the conversion of these dihydro-β-carbolines to naturally occurring eudistomin alkaloids.

Recent Developments in General Methodologies for the Synthesis of α-Ketoamides

“…A nice application of the oxidative amidation/Bischler− Napieralski reaction methodology paved the way to a simple and direct synthesis of β-carbolines, as described by Kumar and co-workers. 138 Thus, dibromoethanones and tryptamine could be oxidatively coupled in DMSO by the action of cumene hydroperoxide, in the presence of NaI and triethylamine (Scheme 47). Under optimized conditions, α-ketoamides were prepared in moderate yields accompanied by benzamide impurities.…”

Recent Advances for the C–C and C–N Bond Formation in the Synthesis­ of 1-Phenethyl-tetrahydroisoquinoline, Aporphine, Homoaporphine­, and β-Carboline Alkaloids

“…Not only natural eudistomins have been described. In 2014 Meruva, Kumar, and co-workers 144 obtained a new series of unexpected 2,9-dihydroeudistomins products during the development of a novel route for the synthesis of some members of the eudistomin Y family. Thus, these unexpected compounds were obtained from tryptamine (186) and 1-aryl-2,2-dibromoethanones 235 furnishing α-ketoamides 236.…”