(NH4)2S2O8-Mediated Metal-Free Decarboxylative Formylation/Acylation of α-Oxo/Ketoacids and Its Application to the Synthesis of Indole Alkaloids

A metal-free method for the formylation/acylation of indoles and beta-carbolines with (NH4)(2)S2O8 via direct decarboxylative cross-coupling of alpha-oxo/ketoacids in moderate to good yields is described. The reaction occurs between ambient temperature and 40 degrees C under mild reaction conditions with commercially available starting materials. This methodology can be expanded to some biologically active indole alkaloids like pityriacitrins, eudistomins Y-1 and Y-3, and marinacarbolines A-D.

Automated summary

A metal-free method for formylation/acylation of indoles and beta-carbolines with (NH4)(2)S2O8 via direct decarboxylative cross-coupling of alpha-oxo/ketoacids is described. The reaction occurs under mild conditions with commercially available starting materials and offers moderate to good yields. This methodology can be applied to various biologically active indole alkaloids.