Pd and photoredox dual catalysis assisted decarboxylative ortho-benzoylation of N-phenyl-7-azaindoles

Directing group assisted decarboxylative ortho-benzoylation of N-aryl-7-azaindoles with α-keto acids has been achieved by synergistic visible light promoted photoredox and palladium catalysis. The approach tenders rapid entry to aryl ketone...

Unexpectedly flexible graphene nanoribbons with a polyacene ladder skeleton

A new conjugated ladder polymer with a polyacene skeleton was synthesized in a Aldol-type condensation protocol between benzylic and aryl-ketone side groups of suitably functionalized single-stranded presursor polymers. The photophysical...

Iodine- and TBHP-Promoted Acylation of Benzothiazoles under Metal-Free Conditions

A simple protocol for the synthesis of 2-acylbenzothiazoles using aryl ketones and benzothiazoles in the presence of I2 and TBHP is described. Acylation of the benzothiazoles is achieved through a sequence involving oxidation of the aryl ketone to an aryl glyoxal, ring-opening of the benzothiazole followed by condensation of the amino group with the aryl glyoxal, cyclization and oxidation. The method avoids the use of metals and toxic solvents. In addition, this protocol has the advantage of broad scope and provides good to excellent product yields.

Rhodium-catalyzed ortho-acrylation of aryl ketone O-methyl oximes with cyclopropenones

We have developed a rhodium-catalyzed ortho-C–H acrylation of O-methyl ketoximes with cyclopropenones leading to the formation of chalcone derivatives.

Acyl radical to rhodacycle addition and cyclization relay to access butterfly flavylium fluorophores

Transition metal-catalyzed C–H activation and radical reactions are two versatile strategies to construct diverse organic skeletons. Here we show the construction of a class of flavylium fluorophores via the merge of radical chemistry and C–H activation starting from (hetero)aryl ketones and alkynes. This protocol is not only applicable to aryl ketones but also to heteroaryl ketones such as thiophene, benzothiophene and benzofuran, thus leading to structural diversity. Mechanism studies, including control experiments, intermediate separation, radical trapping, EPR and ESI-HRMS experiments, demonstrate that the key step lies in the addition of the acyl radical generated by the copper-catalyzed C–C bond cleavage of aryl ketone to the rhodacycle formed via the C–H activation of aryl ketone. The flavylium fluorophores feature butterfly symmetrical configuration, nearly planar skeleton and delocalized positive charge, and exhibit intriguing photophysical properties, such as tunable absorption and emission wavelengths and high quantum yields.

Aryl Ketone Mediated Photoinduced Radical Coupling for the Alkylation­ of Benzazoles Employing Saturated Heterocyclic Compounds­

An aryl ketone mediated synthesis of 2-alkylated benzazoles was achieved via radical coupling under photoirradiation starting from saturated heterocycles and 2-sulfonylated benzazoles, such as benzothiazoles, benzoxazole, and benzimidazole. Heterocyclic compounds, including a cyclic ether, azacycles, and tetrahydrothiophene, were applicable, and the benzazole unit was site-selectively installed at the carbon center proximal to the heteroatom. The present transformation takes place at ambient temperature under neutral reaction conditions without the aid of any metallic catalysts or reagents.