ABSTRACT: The title compound, C(11)H(23)NO(5)P(+)·I(-), consists of an eight-membered cationic heterocyclic ring in a boat-chair conformation. The ring features a tetra-alkyl-ammonium N and a methyl-phospho-nate P atom. A -CH(2)(CO)OC(2)H(5) ester side chain at the C adjacent to oxygen produces two chiral centers at that substituted C atom and the P atom, both of which were determined to have absolute R,R configurations. A previously determined racemic bromide analog has exactly the same ring but with a -C(15)H(31) side chain. In that structure, both chiral centers show the same relative R/S,R/S configurations, but the ring in the bromide analog is in a boat conformation.
Project description:The title compound, C20H29NSi(+)·Br(-), contains a chiral silicon atom but crystallizes as a racemate. The C-Si-C bond angles in the range of 103.64?(8)-111.59?(9)° are usual for tetra-hedral geometry. The piperidine ring shows a regular chair conformation with an equatorially positioned exocyclic N-C bond. In the crystal, there is a hydrogen bond between the ammonium cation and the bromide anion. The crystal packing shows the dominant inter-molecular inter-action to be the electrostatic attraction between the ammonium cation and the bromide anion.
Project description:In the title compound, C(18)H(24)O(4)S, the chiral bicyclo-[2.2.1]heptane group is not symmetrical due to the influence of the substituents. The angle between the three-atom bridge plane and the four-atom planes of the boat-shaped six-membered ring are 55.07?(19) and 56.24?(19)°. The bridgehead angle is 92.75?(17)°.
Project description:In the title compound, C14H16BrN3O5, the N atoms adjacent to the carbonyl group in the five-membered ring are substituted by (1,3-dioxolan-2-yl)methyl groups. The fused ring system is essentially planar, with the largest deviation from the mean plane being 0.014?(2)?Å for the C atom bearing the Br atom. The first oxolane ring, attached on the side of the N atom belonging to the pyridine ring, has an envelope conformation with one of the O atoms as the flap, whereas the second oxolane ring displays a twisted boat conformation. The two oxolane rings display envelope and twisted boat conformations. In the crystal, mol-ecules are linked by C-H?O hydrogen bonds, building chains parallel to the a-axis direction.
Project description:In the title compound, [PdCl2(C17H28N2)], the Pd(II) atom displays a square-planar coordination involving two N atoms of a 2,6-diisopropyl-N-[(S)-pyrrolidin-2-ylmeth-yl]aniline ligand and two chloride ligands, with a deviation of 0.090?(1)?Å for the Pd(II) atom from the best plane. The absolute configuration of the chiral C atom of the pyrrolidine ring is S, which induces R configurations at the two N atoms of the aniline ligand. Optical isomerism arising from the chelate five-membered ring is configured as ?. The Pd-N bond lengths are 2.040?(3) and 2.072?(2)?Å, and the Pd-Cl bond lengths are 2.3055?(8) and 2.3160?(8)?Å. In the crystal, pairs of N-H?Cl hydrogen bonds link mol-ecules into discrete dimers.
Project description:The title compound, [Li2(C25H23BN4OP)2], features a centrosymmetric dimeric complex. The four-memberered Li2O2 ring is exactly planar due to symmetry. The Li atom is four-coordinated by two O atoms and by two N atoms of two different pyrazole rings. The dihedral angle between two pyrazole rings bonded to the same B atom is 45.66?(9)°. The B-N-N-Li-N-N metalla ring adopts a boat conformation. The crystal packing is stabilized by van der Waals inter-actions only.
Project description:In the title compound, C(28)H(35)N(3)O(4), the piperidine ring adopts a boat conformation while the piperazine ring adopts a chair conformation with an equatorial orientation of the phenyl groups. The dihedral angle between the mean planes of the benzene rings is 74.14?(8)°. The mol-ecular conformation is stabilized by a weak intra-molecular C-H?N inter-action and the crystal packing is stabilized by weak inter-molecular C-H?O inter-actions.
Project description:In the title compound, C(20)H(22)N(2)O(4)S, the central pyrimidine ring incorporating a chiral C atom is significantly puckered and adopts a slight boat conformation with C atom bearing the phenyl ring and the N atom opposite displaced by 0.367?(2) and 0.107?(2)?Å, respectively, from the plane formed by the remaining ring atoms. The benzene ring is positioned axially to the pyrimidine ring, making a dihedral angle of 88.99?(5)°. The thia-zole ring is essentially planar (r.m.s. deviation = 0.0033?Å). In the crystal, pairs of C-H?O inter-actions result in centrosymmetric dimers with graph-set motifs R(1) (2)(7) and R(2) (2)(8). A weak C-H?? contact is also observed.
Project description:The mol-ecule of the title compound, C(22)H(23)N(3)O(4), features a benzodiazepine fused-ring system whose seven-membered ring adopts a boat-shaped conformation (with the C atoms of the fused-ring as the stern and the methine C atom as the prow). The methyl-ene C atom connected to the methine C atom occupies an equatorial position. The methyl-ene C atom is connected to the five-membered oxazole ring, both of which are disordered over two positions in a 0.634?(4):0.366?(4) ratio. Weak inter-molecular C-H?O hydrogen bonding is present in the crystal structure.
Project description:In the title compound, C(18)H(21)N(5)O(4), the diazepine ring adopts a boat conformation with the triazolylmethyl-bearing C atom as the prow and the C atoms at the ring junction as the stern.
Project description:The title chiral compound, C(23)H(28)NO(+)·Br(-), was obtained from an optically active amino-ethanol precursor. The pyrrolidine heterocycle has an envelope conformation, with the C atom ?-positioned with respect to the keto group deviating by 0.570?(6)?Å from the mean plane of other atoms. The trans-fused seven-membered ring adopts a pseudo-chair conformation. The two phenyl rings form a dihedral angle of 85.1?(2)°. The cationic center and the bromide anion are connected through an N-H?Br hydrogen bond.