Palladium(II)-catalyzed direct intermolecular alkenylation of chromones

Palladium-catalyzed direct alkenylation of 2-methyl-4H-pyrido[1,2-a]pyrimidin-4-ones using oxygen as the oxidant

A direct C-3 alkenylation of 2-methyl-4H-pyrido[1,2-a]pyrimidin-4-ones through palladium-catalyzed C–H activation using oxygen as the terminal oxidant has been developed.

Palladium(ii)-catalyzed direct alkenylation of dihydropyranones

A palladium(ii)-catalyzed direct alkenylation reaction of dihydropyranones was developed.

Regioselective palladium(ii)-catalyzed aerobic oxidative Heck-type C3 alkenylation of sulfocoumarins

An efficient method for the direct C–H olefination of sulfocoumarins with a wide range of alkenes is developed. Moreover, O₂ was successfully utilized as the sole oxidant for the oxidative Heck reaction. This approach enables the rapid generation of various 3-alkenylated sulfocoumarins.

Synthesis of heterocyclic-fused benzofurans via C-H functionalization of flavones and coumarins

An efficient method to effect C-O cyclization was developed via the C-H functionalization of chromones and coumarins, affording heterocyclic-fused benzofurans.

Synthesis of heterocyclic-fused benzopyrans via the Pd(ii)-catalyzed C–H alkenylation/C–O cyclization of flavones and coumarins

An efficient and practical method for effecting a tandem C–H alkenylation/C–O cyclization has been achieved via the C–H functionalization of flavone derivatives.

Synthesis of 3-(4-oxo-4H-chromen-3-yl)acrylates through the tandem reaction of 3-(2-buta-2,3-dienoylphenoxy)acrylates

A straightforward and efficient synthesis of 2-substituted 3-(4-oxo-4H-chromen-3-yl)acrylates through base-catalyzed tandem reaction of the readily available 3-(2-buta-2,3-dienoylphenoxy)acrylates under extremely mild conditions has been developed.

Transition metal-catalyzed C(vinyl)-C(vinyl) bond formation via double C(vinyl)-H bond activation

Transition metal-catalyzed oxidative dehydrogenative coupling reactions of Caryl-H bonds with Cvinyl-H bonds to generate a Caryl-Cvinyl bonds have been well developed in recent decades. However, only a few studies have focused on the direct Cvinyl-Cvinyl bond formation via double Cvinyl-H bond activation. Recent developments in this active area have been highlighted in this tutorial review.

1-(3-Chloro-phen-yl)-5-(2,4-di-hydroxy-benzo-yl)pyridin-2(1H)-one

The chloro-phenyl group of the title compound, C18H12ClNO4, is disordered over two orientations with occupancies of 0.331 (8) and 0.669 (8). An intra-molecular hydrogen bond is formed between a hy-droxy group and the acyclic carbonyl group. In the crystal, molecules are linked into chains along [110] by O-H⋯O and C-H⋯O hydrogen bonds, forming a ladder motif.

A highly tunable stereoselective dimerization of methyl ketone: efficient synthesis of E- and Z-1,4-enediones

A new method for the tunable synthesis of 1,4-enedione directly from aromatic methyl ketone is described. This tandem reaction enables the construction of symmetric and unsymmetric 1,4-enediones with complete E-selectivity. Moreover, the resulting E-1,4-enedione could be transformed into a Z-isomer by irradiation with 23 W of white light.

Regioselective palladium-catalyzed olefination of coumarins via aerobic oxidative Heck reactions

Pd-catalyzed oxidative Heck reactions of coumarins were developed via simultaneous C-H functionalization at the C3 position of coumarins under aerobic conditions.

Palladium(II)-catalyzed direct alkenylation of nonaromatic enamides

A mild and efficient method for the direct alkenylation of nonaromatic enamides was achieved through a palladium(II)-catalyzed C-H functionalization. The reaction scope includes cyclic and acyclic enamides and a range of activated alkenes. This approach represents the first successful direct C(3)-functionalization of nonaromatic cyclic enamides.

Palladium(II)-catalyzed dehydrogenative alkenylation of cyclic enaminones via the Fujiwara-Moritani reaction

A new Pd(II)-catalyzed dehydrogenative alkenylation reaction involving two alkenes was developed. A variety of nonaromatic, cyclic enaminones were successfully coupled to primary and secondary alkenes yielding a series of unique 1,3-dienes. The generality of this transformation presents a useful strategy for directly cross-coupling alkenes and offers an attractive new approach to functionalize enaminones.