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.

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.

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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