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The divergent synthesis of dihydropyrimidouracil and pyrimidouracil derivatives from N‐uracil amidines and tertiaryamines by an oxidative C(sp3)−N cleavage cascade cyclization reaction is first described. This transformation enables the formation of new C(sp3)−N and C(sp2)−N bonds via the selection of different oxidation conditions. The features of this method include tunable product selectivity, excellent chemoselectivity, readily available starting materials, broad substrate scope, good tolerance of functional groups, and moderate to high yields. [ABSTRACT FROM AUTHOR]

Using benzylamines as the C4 source of 1,4‐dihydropyridines (1,4‐DHPs), a Cu‐catalyzed oxidative [1+2+1+2] cascade cyclization for the synthesis of 1,4‐DHPs was firstly developed. A broad range of easily available N,N‐dimethyl enaminones and benzylamines are employed smoothly to provide a diverse range of 1,4‐DHPs with high efficiency. This method is performed by a one‐pot cascade C(sp3)−H bond functionalization/C(sp3)−N cleavage/cyclization strategy to form simultaneously two C(sp3)−C(sp2) bonds, two C(sp2)−N bonds, and a 1,4‐DHP ring. [ABSTRACT FROM AUTHOR]

An oxidative [3+2+1] cyclization of enaminones and N‐alkenyl‐2‐pyrrolidinone is described for the synthesis of 4‐alkylated 1,4‐dihydropyridines (1,4‐DHPs). By using terminal olefin as the C4 source of the 1,4‐DHP skeleton, this synthetic strategy provides a series of 1,4‐DHPs through a 1,1‐difunctionalization/cyclization process. In this protocol, two C(sp3)−C(sp2) bonds and a C(sp2)−N bond are simultaneously formed, the hydrogen source on the newly formed methyl group of the 1,4‐DHP skeleton is confirmed and a possible mechanism is proposed. [ABSTRACT FROM AUTHOR]

A silver‐catalyzed protocol for the synthesis of 3‐(1H‐isochromen)‐chromones is described. The method involves an initial 6‐endo‐dig cyclization of o‐alkynylbenzaldehydes and domino C−H alkylation and chromone annulation of the o‐hydroxyarylenaminones, which enables the installation of 1H‐isochromen and chromone in a single structure. This synthetic strategy is advantageous for the excellent regioselectivity, step economy, concise one‐pot methodology, gram‐scale synthesis, as well as high bond‐forming efficiency. [ABSTRACT FROM AUTHOR]

The C(sp2)−H phosphorothiolation involving cyclization process through a transition‐metal‐free strategy is reported. It provides an attractive approach for the construction valuable S‐3‐chromon phosphorothioates from o‐hydroxyarylenaminones and P(O)SH compounds in the presence of 1.0 equiv. of iodine at 60 °C. This novel protocol shows readily available chemicals, broad substrate scope, and mild reaction conditions. [ABSTRACT FROM AUTHOR]

Copper(II)‐mediated unprecedented intermolecular radical [3+2] annulation of N,N‐dimethyl enaminones has been developed. The protocol is promoted simply by copper(II) chloride to access 5‐acyl‐3‐furancarboxaldehydes with acceptable to good yields and broad substrate scope. This reaction allows the formation of multiple new bonds, including C(sp2)−O bond between two nucleophilic sites, C(sp2)−C(sp2) bond and C=O bond, through a radical cyclization process. Moreover, gram‐synthesis and application research show the potential application value of this transformation in industry. [ABSTRACT FROM AUTHOR]