One-Pot Synthetic Approach to Dipyrromethanes and Bis(indolyl)methanes via Nitrosoalkene Chemistry

• DOI: 10.1021/acs.jchemed.1c00184
• Publication Date: 2021-07-23T16:31:37Z
• Authors: Ana L. Cardoso; Susana M. M. Lopes; Carla Grosso; Marta Pineiro; Américo Lemos; Teresa M. V. D. P...
• Keywords: Reactivity; Pyrrole; Organic reaction; Organic Synthesis

A one-pot regio- and stereoselective synthesis of a dipyrromethane bis(indolyl)methane based on two consecutive reactions nitrosoalkenes with pyrrole or indole, respectively, is described as an experiment to be carried out by upper-division undergraduate students in laboratory classroom. Importantly, the ability electrophilic conjugated react via Michael addition hetero-Diels–Alder electron-rich heterocycles will provide opportunity for acknowledge alternative reaction pathways underlying certain transformations. Reactions were performed under mild conditions using water solvent, followed purification through column chromatography silica gel, characterization desired products NMR IR spectroscopy. This combines organic synthesis, determination purity compounds (TLC analysis melting point measurements), well structural (interpretation 1D spectra). Several important chemistry concepts, such stereo- regioselectivity, situ generation reactivity nitrosoalkenes, 1,4-addition reactions, cycloaddition are also discussed.