Multimodal study of secondary interactions in Cp*Ir complexes of imidazolylphosphines bearing an NH group.

Hydrogen bonding phenomena are explored using a combination of X-ray diffraction, NMR and IR spectroscopy, and DFT calculations. Three imidazolylphosphines R(2)PImH (ImH = imidazol-2-yl, R = t-butyl, i-propyl, phenyl, 1a-1c) and control phosphine (i-Pr)(2)PhP (1d) lacking an imidazole were used to make a series of complexes of the form Cp*Ir(L(1))(L(2))(phosphine). In addition, in order to suppress intermolecular interactions with either imidazole nitrogen, 1e, a di(isopropyl)imidazolyl analogue of 1b was made along with its doubly (15)N-labeled isotopomer to explore bonding interactions at each imidazole nitrogen.

Anhydrides of real and hypothetical [hydroxy(R-O)iodo]benzenes.

The anhydrides of [hydroxy(methanesulfonato-O)]iodobenzene (HMIB) and [hydroxy(toluenesulfonato-O)]iodobenzene (HTIB) were prepared by drying acetonitrile solutions of the compounds. The anhydrides of the hypothetical compounds [hydroxy(chloroacetato)-O]iodobenzene and [hydroxy(iodoacetato)-O]iodobenzene were obtained from aqueous solutions. Crystallographic structures were obtained for the anhydrides, except that of HTIB.

Reversible Ligand Pairing and Sorting Processes Leading to Heteroligated Palladium(II) Complexes with Hemilabile Ligands.

Halide-induced ligand pairing and sorting processes have been observed in the context of Pd(II) complexes with hemilabile P,S and P,O ligands. Mixing of the ligands PhPCHCHSMe () and PhPCHCHSPh () with a Pd(II) precursor in CHCl results in a mixture of [()ClPd]Cl, [()ClPd], and [()()ClPd]Cl complexes at 20 °C. This equilibrium can be driven toward the heteroligated structure [()()ClPd]Cl by (1) cooling the mixture or (2) precipitation with hexanes, leading to the exclusive formation of semiopen heteroligated complex -[ -()- -()ClPd]Cl (), as confirmed by a single-crystal X-ray diffraction study and solid state CPMAS P{H} NMR spectroscopy.

Platinum-catalyzed enantioselective tandem alkylation/arylation of primary phosphines. Asymmetric synthesis of P-stereogenic 1-phosphaacenaphthenes.

Enantioselective tandem alkylation/arylation of primary phosphines with 1-bromo-8-chloromethylnaphthalene catalyzed by Pt(DuPhos) complexes gave P-stereogenic 1-phosphaacenaphthenes (AcePhos) in up to 74% ee. Diastereoselective formation of four P-C bonds in one pot with bis(primary) phosphines gave C2-symmetric diphosphines, including the o-phenylene derivative DuAcePhos, for which the rac isomer was formed with high enantioselectivity. These reactions, which appear to proceed via an unusual metal-mediated nucleophilic aromatic substitution pathway, yield a new class of heterocycles with potential applications in asymmetric catalysis.

Structure activity relationships of 5-, 6-, and 7-methyl-substituted azepan-3-one cathepsin K inhibitors.

The syntheses, in vitro characterizations, and rat and monkey in vivo pharmacokinetic profiles of a series of 5-, 6-, and 7-methyl-substituted azepanone-based cathepsin K inhibitors are described. Depending on the particular regiochemical substitution and stereochemical configuration, methyl-substituted azepanones were identified that had widely varied cathepsin K inhibitory potency as well as pharmacokinetic properties compared to the 4S-parent azepanone analogue, 1 (human cathepsin K, K(i,app) = 0.16 nM, rat oral bioavailability = 42%, rat in vivo clearance = 49.