A practical and highly enantio- (up to 94:6 er) and diastereoselective (up to >20:1 dr) synthesis of γ-butenolides bearing two adjacent stereogenic centers is reported featuring a sequential direct palladium-catalyzed asymmetric allylic alkylation/(E)-selective cross-metathesis/[3,3]-sigmatropic Cope rearrangement from readily available α-substituted (5H)-furan-2-ones.

The first direct 3-alkenylation of N-substituted 4-hydroxy-2-pyridones with unactivated alkenes is reported through a palladium acetate catalyzed, oxidative coupling.

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A selective, practical and scalable aerobic oxidation of alcohols is described using catalytic amounts of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and HNO 3 , with molecular oxygen serving as the terminal oxidant. The method was successfully applied to the oxidation of a wide range of benzylic, propargylic and allylic alcohols, including two natural products, namely carveol and podophyllotoxin. The conditions are also applicable to the selective oxidative deprotection of PMB ethers.

Tosylhydrazones under palladium catalysis were found to perform cross-coupling reactions with 4-hydroxy-2pyridones. The umpolung-like reactivity, between the α-carbon of tosylhydrazone and the 3-position of the heterocycle, which is observed in the obtained products, indicates the directed sp 3 -CHactivation of an alkylated phenol intermediate by the pendant 3-palladated heterocycle. The reaction and its intercepted variants are surveyed in their scope, allowing the synthesis of inaccessible 3-carbocyclic pyridones in moderate to excellent yields.CH-activation of 2-pyridone heteroaromatic ring has attracted considerable attention in recent years. 1 CH-functionalization at the 3-position is mainly relying on radical mediators, such as nickel, manganese, iron, and iridium complexes, 2 whereas the functionalization of the 5-position is almost exclusively dependent on palladium chemistry (Figure 1). 3 However, the electron Letter pubs.acs.org/OrgLett