Passerini–Smiles Reaction of α‐Ketophosphonates: Platform for Phospha‐Brook/Smiles Embedded Cascades

Abstract The Passerini–Smiles reactions of α‐ketophosphonates with nitrophenols has been used as a platform to observe complex cascades involving multiple Smiles transfers coupled with phospha‐Brook rearrangement. When using 4‐nitrophenols a rare 1,3‐Truce–Smiles rearrangement is observed leading to diarylacetamide derivatives. 2‐Nitro‐derivatives lead to a completely different reactivity pattern that may be explained by a nitro to nitroso conversion followed by a σ–π metathesis. All mechanistic assumptions are confirmed by DFT calculations performed on both families of adducts. The potential of this work has been further demonstrated by the use of N‐aryl α‐ketoamides as alternative starting materials for these cascades as well as the disclosure of new aza‐Nazarov access to hydroxy‐indolones.