An efficient Bi(OTf)3‐catalyzed transformation of unprotected propargylic alcohols has been developed, affording a general, one‐pot approach to access diverse pyrazoles via sequential iodo‐intercepted Meyer‐Schuster rearrangement, cyclocondensation of NH2NH2 ⋅ H2O and α‐iodo enones/enals generated in situ, and iodine elimination. This transformation tolerates a wide range of substrates and is reliable on a large scale. The high yields and convenient experimental operations make it a valuable method for the construction of pyrazole derivatives.

A one-pot conversion of o-anilinopropargyl alcohols to 3-aryliden-2,3-dihydro-4-quinolone derivatives with 20 mol% TfOH as the catalyst has been devised. The method may proceed through a sequential Meyer-Schuster rearrangement of o-anilinopropargyls/intramolecular conjugated addition/aldol condensation of in situ generated 2,3-dihydroquinolin-4-ones and aldehydes. Finally, the subsequent additions succeeded between 3-benzyliden-2,3-dihydro-4-quinolones and hydrazines to give fused multicycles. The reaction is metal-and ligand-free, proceeds under mild conditions, gives high yields, and has a broad substrate scope, making it a valuable method for the construction of 3-aryliden-2,3dihydro-4-quinolone functionalized building blocks.

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An alkyl intercepted Meyer–Schuster rearrangement reaction with α,β-unsaturated ketones as the electrophiles was first investigated, which provided a facile method to construct 2-methylene-pentane-1,5-diones. Then the in situ generated 2-methylene-pentane-1,5-diones underwent a Michael addition to give diverse 2-malononitrile methyl substituted pentane-1,5-diones in a one-pot fashion. This transformation was reliable on a gram scale. The high yield, convenient experimental operation, and 100% atom economy made it a valuable method for the construction of 1,2,3,5-tetrasubstituted pentane-1,5-dione derivatives.