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An example of asymmetric Steglich-type rearrangement of enol lactones is reported. This highly enantioselective acyl transfer reaction is catalyzed by chiral isothiourea at ambient temperature and provides a useful synthetic approach to access enantioenriched spirotricyclic β,β'-diketones from a broad range of indanone or tetralone-derived lactones. Preliminary mechanistic studies suggest the initial formation of an N -acylated iminium cation intermediate that induces a following facial selective condensation.

An asymmetric intramolecular hydroalkylation of unactivated internal olefins with tethered cyclic ketones was realized by the cooperative catalysis of a newly designed chiral amine (SPD‐NH2) and PdII complex, providing straightforward access to either bridged or fused bicyclic systems containing three stereogenic centers with excellent enantioselectivity (up to 99 % ee) and diastereoselectivity (up to >20 : 1 dr). Notably, the bicyclic products could be conveniently transformed into a diverse range of key structures frequently found in bioactive terpenes, such as Δ6‐protoilludene, cracroson D, and vulgarisins. The steric hindrance between the Ar group of the SPD‐NH2 catalyst and the branched chain of the substrate, hydrogen‐bonding interactions between the N−H of the enamine motif and the C=O of the directing group MQ, and the counterion of the PdII complex were identified as key factors for excellent stereoinduction in this dual catalytic process by density functional theory calculations. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mechanism of DABCO mediated-[4+4] domino annulation reaction were theoretically investigated. • The reactivity tendency of possible reaction sites in the reactants was evaluated. • The role of DABCO in the hydrogen abstraction reaction was illustrated. As natural products with important biological activities, eight-membered cyclic ethers can be achieved in good yields by the [4 + 4] domino annulation reactions of ynones and α-cyano-α,β-unsaturated ketones mediated by DABCO under mild conditions. To figure out the detailed reaction mechanism, quantum mechanical calculations were carried out. The global and local reactivity indexes were employed to evaluate the nucleophilic or electrophilic property and reactivity tendency of possible reaction sites in the reactants. Quantum theory of atoms in molecules were used to illustrate the intermolecular interactions formed in the complexes and transition states. The results indicate that two possible pathways exist for the [4 + 4] domino annulation reaction, and they were compared to figure out which one is more feasible and favorable. The important role of DABCO in the reaction was illustrated. [ABSTRACT FROM AUTHOR]