In the title compound, C(11)H(12)ClNO(3), the dihedral angle between the benzene ring and the amide group is 44.9 (2)°. In the crystal, mol-ecules form inversion dimers via pairs of O-H⋯O hydrogen bonds. These dimers are further linked into sheets parallel to (013) via N-H⋯O hydrogen bonds.

In the crystal structure of the title compound, C16H24N4O4, mol-ecules are linked by N-H⋯O hydrogen bonds between the carbonyl groups of the carbamoyl and amido functional groups and the amino groups, and by N-H⋯N hydrogen bonds between the amino group and the pyridine ring, forming two-dimensional networks parallel to the ab plane.

In the crystal of the title compound, C(11)H(12)O(4), inversion dimers arise from pairs of intermolecular O-H⋯O hydrogen bonds and C-H⋯O bonds further consolidate the packing. There is also a C-H⋯π contact between the benzene ring and the methyl-ene group.

The non-H atoms of the title compound, C20H20N2O2, is located on a mirror plane except two methyl groups of the tert-butyl group. Intra-molecular N-H⋯O hydrogen bonds exist between the hy-droxy and diazenyl groups. In the crystal, mol-ecules are linked by weak C-H⋯O hydrogen bonds into supra-molecular chains running along the a-axis direction.

The creation of carbon-carbon and carbon-heteroatom bonds by the oxidation of organocuprates is useful in a range of challenging contexts including the formation of biaryl bonds within medium rings, diene synthesis and the coupling of tertiary carbon centres. This tutorial review introduces these applications and recent developments which have served to improve its functional group tolerance an...

In the title compound, C(9)H(17)N(2) (+)·C(17)H(15)N(2)O(2)S(2) (-), the Csp(2)-N bonds in the tetra-hydro-pyrimidine ring of the cation are delocalized. The negative charge is localized on the S atom of the thione group. Cations and anions are linked by N-H⋯S inter-molecular hydrogen bonds.

In the title mol-ecule, C18H18O4, the C=C bond of the central enone group adopts a trans conformation. The relative conformation of the C=O and C=C bonds is s-cisoid. The dihedral angle between the planes of the benzene rings is 29.49 (12)°. In the crystal, weak C-H⋯O hydrogen bonds link the mol-ecules into chains along [010].

In the title mol-ecule, C(8)H(7)BrO(2), the carboxyl group is twisted by 76.2 (3)° from the benzene ring plane. In the crystal, mol-ecules are linked into inversion dimers through pairs of O-H⋯O hydrogen bonds. The dimers are further linked into layers parallel to the bc plane by weak C-H⋯O hydrogen bonds.