Synthesis of Hybrid Chromone/Coumarin 3-Halo-1H-indenes
BX3-Mediated Intermolecular Formation of Functionalized 3-Halo-1H-indenes via Cascade Halo-Nazarov-Type Cyclization: A. Kumari, R. A. Fernandes
Synthesis 2020, 52, DOI: 10.1055/s-0039-1690881
Indenes and chromones are widespread molecular scaffolds present in a plethora of natural compounds. They represent prominent targets in synthetic organic chemistry and their combination in a hybrid molecule could impart beneficial bio-pharmaceutical properties. With this concept in mind, the group of Professor Rodney A. Fernandes from the IIT Bombay (Mumbai, India) recently developed a simple and effective route to chromone- and coumarin-substituted 3-halo 1H-indenes.
Professor Fernandes said: “An intermolecular regioselective synthesis of 3-halo-functionalized 1H-indenes from 4-oxo-4H-chromene-3-carbaldehydes and alkynes has been developed promoted by BX3 (X = halide). The latter displays a dual role of Lewis acid catalyst and halide source for halo-allyl cation formation for the intended halo-Nazarov-type cyclization with two new C–C and one C–X bonds formed.”