Construction of indeno[1,2-b]pyrroles via chemoselective N-acylation/cyclization/Wittig reaction sequence

Phosphine-Catalyzed Chemoselective Reduction/Elimination/Wittig Sequence for Synthesis of Functionalized 3-Alkenyl Benzofurans

An efficient protocol for the construction of functionalized 3-alkenyl benzofurans is demonstrated under metal-free conditions using catalytic amount of phosphine proceeding an intramolecular Wittig reaction. This one-pot reaction initiated by the phospha-Michael addition of phosphine to O-acylated nitrostyrene, in which phosphine was in-situ-generated from the chemoselective reduction of phosphine oxide with PhSiH₃, would provide the phosphorus ylide to result in the aforementioned multifunctionalized benzofuran via O-acylation/nitrous acid elimination/Wittig reaction.