Chiral spiropyrazolones were constructed through Pd-catalyzed asymmetric sequential hydroalkylation of 1,3-enynes. Four stereoisomers could be obtained through substrate control and chiral ligand control.
Highly functionalized fluoroalkyl spiropyrazolones are synthesized via an effective [3 + 2] cycloaddition of di/trifluoromethyl hydrazonoyl bromides and alkylidene pyrazolones in good yields.
NaH-mediated synthesis of spiro-pyrazolone–pyrrolidinones using arylidine pyrazolones and 2-chloro-N-phenylacetamides is developed. Features are atom and step economy, mild conditions, short reaction time, gram scale reaction and good yields.
Asymmetric synthesis of fluoro-perhydroepoxyethanoindole was achieved through a sequential aminocatalytic [4 + 2]-addition/reduction/fluoroannulation reactions.
A palladium-catalyzed general synthetic strategy to access an attractive and decorated set of spirooxazinane skeletons was successfully achieved using vinyl benzoxazinanone derivatives and ketones.