In(iii)-Catalyzed tandem reaction of chromone-derived Morita–Baylis–Hillman alcohols with amines

Crystal structure of C24H23NO3

C24H23NO3, orthorhombic, Pna21, a = 8.2490(11) Å, b = 15.886(2) Å, c = 16.218(2) Å, β = 99.465(2)°, Z = 4, V = 2096.4(5) Å3, R gt (F) = 0.0545, wR ref (F 2) = 0.1688, T = 273 K.

Catalytic enantioselective synthesis of tetrasubstituted chromanones via palladium-catalyzed asymmetric conjugate arylation using chiral pyridine-dihydroisoquinoline ligands

Highly enantioselective conjugate addition reactions of arylboronic acids to 2-substituted chromones catalyzed by palladium complexes with new chiral Pyridine-Dihydroisoquinoline (PyDHIQ) ligands have been developed. These reactions provide highly enantioselective access to chromanones containing tetrasubstituted stereocenters. Various arylboronic acids and 2-substituted chromones can be used in the catalytic reaction to afford the chiral tetrasubstituted chromanones in good yields and excellent enantioselectivities (25 examples, up to 98% yields, up to 99% ee).

Crystal structures of (E)-3-(4-hy-droxy-benzyl-idene)chroman-4-one and (E)-3-(3-hy-droxy-benzyl-idene)-2-phenyl-chroman-4-one

The synthesis and crystal structures of (E)-3-(4-hy-droxy-benzyl-idene)chroman-4-one, C16H12O3, I, and (E)-3-(3-hy-droxy-benzyl-idene)-2-phenyl-chroman-4-one, C22H16O3, II, are reported. These compounds are of inter-est with respect to biological activity. Both structures display inter-molecular C-H⋯O and O-H⋯O hydrogen bonding, forming layers in the crystal lattice. The crystal structure of compound I is consolidated by π-π inter-actions. The lipophilicity (logP) was determined as it is one of the parameters qualifying compounds as potential drugs. The logP value for compound I is associated with a larger contribution of C⋯H inter-action in the Hirshfeld surface.

Unprecedented formation of 3-(tetrahydrofuran-2-yl)-4H-chromen-4-one in a reaction between 3,3a-dihydro-9H-furo[3,4-b]chromen-9-one and malononitrile

Chromone skeletons are widespread among natural products as well as bioactive molecules. Here, we describe an unprecedented reaction of furo[3,4-b]chromen-9-one with malononitrile to afford 3-(tetrahydrofuran-2-yl)-4H-chromen-4-ones. Experimental data suggest that a sequence of Michael/retro-Michael/nucleophilic addition is involved in this unprecedented transformation.

A highly enantioselective access to chiral chromanones and thiochromanones via copper-catalyzed asymmetric conjugated reduction of chromones and thiochromones

The chromanone scaffold is a privileged structure in heterocyclic chemistry and drug discovery.

Reactions of nitroxides XIII: Synthesis of the Morita-Baylis-Hillman adducts bearing a nitroxyl moiety using 4-acryloyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl as a starting compound, and DABCO and quinuclidine as catalysts

The Morita-Baylis-Hillman adducts bearing a nitroxyl moiety were synthesized from 4-acryloyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl and aliphatic, aryl and heterocyclic aldehydes.