In the title compound, C(19)H(21)NO(4), an organocatalyst with a tetra-hydro-isoquinoline backbone, the heterocyclic ring assumes a half-boat conformation. The dihedral angle between the aromatic rings is 82.93 (8)°. In the crystal, mol-ecules are linked via N-H⋯O and C-H⋯O hydrogen bonds, forming a layer parallel to (10[Formula: see text]).

There are two independent mol-ecules in the asymmetric unit of the title compound, C(24)H(22)N(2)O(3). The heterocyclic ring assumes a twisted boat conformation and N-H⋯O inter-actions help to construct the three-dimensional network within the crystal packing.

The title compound, C(22)H(19)NO(2), has potential for use as a new nonlinear optical material. Mol-ecules are almost planar. One C atom of the heterocyclic ring system is disordered over two positions; the site occupancy factors are 0.6 and 0.4.

In the crystal structure of the title compound, C(28)H(36)O(4)S, the p-tolyl ring is inclined at 35.8° to the aromatic ring. The cyclohexene ring adopts a boat conformation and the heterocyclic ring is in a slightly distorted screw boat conformation.

In the title compound, C(10)H(9)NOS(2), the five-membered heterocyclic ring and the benzyl moiety are oriented at a dihedral angle of 77.25 (4)°. In the crystal, infinite polymeric C(6) chains extending along [001] are formed due to C-H⋯O hydrogen bonds. C-H⋯π inter-actions link the chains, building up a three-dimensional network.

The title compound, C(17)H(18)BrN(3)OS, is an important inter-mediate for the synthesis of biologically active heterocyclic compounds. The thio-urea group is approximately planar. The crystal structure is stabilized by inter-molecular N-H⋯O hydrogen-bonding inter-actions.

In the title compound, C(14)H(10)N(2)O(2), the dihedral angle between the heterocyclic ring system and the phenyl ring is 45.8 (5)°. Weak inter-molecular C-H⋯N hydrogen bonding is present in the crystal structure.

The title compound, C(27)H(40)O(4), was obtained from the oxidation of (25R)-3b-hydr-oxy-5a-spiro-stan-12-one (Hecogenin) by Jone's reagent. The mol-ecule contains six alicyclic and heterocyclic rings, all trans-fused, among which four six-membered rings adopt similar chair conformations while two five-membered rings assume an envelope conformation.

In the title compound, C(20)H(21)NO(3), the heterocyclic six-membered ring adopts a half-chair conformation and the pyrrolidine ring adopts an envelope conformation. The mol-ecular conformation is stabilized by C-H⋯O and C-H⋯N inter-actions.

Two tridentate N-heterocyclic ligands chelate the Zn(II) atom in the title compound, [Zn(C(12)H(16)N(4))(2)](PF(6))(2), conferring a fac-octa-hedral geometry. The Zn(II) atom lies on a center of inversion. The cation is linked to the anion by an N-H⋯F hydrogen bond.