Phosphine-promoted intramolecular Rauhut–Currier/Wittig reaction cascade to access (hetero)arene-fused diquinanes

We describe the first phosphine-promoted intramolecular Rauhut–Currier reaction that triggers an intramolecular Wittig process assembling new classes of diquinanes. The one-pot strategy provides ready access to simple diquinanes and various (hetero)arene-fused diquinanes incorporated with up to two contiguous all-carbon quaternary centers under metal-free and neutral conditions. We showcased the generality of the method on a broad range of substrates and demonstrated its synthetic utility in accessing various advanced intermediates relevant to natural product synthesis and material science.