An atom-economic approach to the regio- and stereoselective assembly of highly substituted enamides is described via the Pd-catalyzed chloroallylation of ynamides at room temperature, which offers a simple and practical alternative to the stereodefined multisubstituted enamides.

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A Pd-catalyzed coupling of haloalkynes with allyl acetate has been reported, providing a convenient method for the stereoselective synthesis of (Z)-β-haloenol acetates in good yields. The synthetic utility of this method is demonstrated by the formation of functionalized enol acetates via the Suzuki-Miyaura or Sonogashira coupling of the resulting (Z)-β-haloenol acetate products.

A visible-light-induced 1,1-hydrofluoroalkylation of alkynes with a concomitant vicinal acylation is developed using tetrahydrofuran (THF) as the hydrogen atom source. Various fluoroalkylated cyclic ketones, such as indanones, chroman-4-ones, 2,3-dihydroquinolin-4­(1H)-ones, and 3,4-dihydronaphthalen-1­(2H)-ones, can be efficiently synthesized with excellent trans-diastereoselectivity. The reaction represents the first example of 1,1-hydrofluoroalkylation of alkynes, thus providing a novel method for the construction of fluoroalkanes.

Described herein is a novel method for the synthesis of 3,4,5-trisubstituted 2-oxazolones featuring the first Pd-catalyzed dehydrogenative alkenylation of 2-oxazolones, which is realized by employing 10 mol % of Pd(OAc)2 as the catalyst and the use of readily available Cu(OAc)2 as the oxidant. A wide range of functional groups, such as F, Cl, Br, OMe, ester, ketone, amide, alkyl, and aryl substituents, are found to be compatible under the reaction conditions. The utilization of the C-H functionalization strategy provides a straightforward, convenient, and highly atom-economical approach for the construction of 3,4,5-trisubstituted 2-oxazolones. It is worth noting that the 4-alkenyl 2-oxazolones can be smoothly converted into naphtho[1,2-d]oxazol-2-ones via a photochemical transformation.