@article {2549, title = {Synthetic Approaches to the Microtubule-Stabilizing Sponge Alkaloid Ceratamine A and Desbromo Analogues}, journal = {Journal of Organic Chemistry}, volume = {74}, number = {3}, year = {2009}, note = {ISI Document Delivery No.: 402HHTimes Cited: 6Cited Reference Count: 58Nodwell, Matt Pereira, Alban Riffell, Jenna L. Zimmerman, Carla Patrick, Brian O. Roberge, Michel Andersen, Raymond J.}, month = {Feb}, pages = {995-1006}, type = {Article}, abstract = {Two synthetic approaches to the microtubule-stabilizing ceratamine alkaloids are described. The first approach involved attempts to graft an aminoimidazole moiety onto an azepine ring to form partially hydrogenated versions of the unprecedented aromatic imidazo[4,5-d]azepine core of the ceratamines. This route ultimately failed because it was not possible to aromatize the partially hydrogenated ceratamine intermediates. A second approach started with tribromoimidazole that was sequentially metalated and functionalized to efficiently generate a key imidazole intermediate containing vinyl bromide and amide functionalities. An intramolecular Buchwald vinyl amidation reaction converted this key intermediate into a bicyclic imidazol[4,5-d]azepine that was at the same oxidation state as the aromatic core of the ceratamines. The 2-amino functionality present on the imidazole ring of the ceratamines was installed using a Buchwald/Hartwig amination reaction on a 2-chloroimidazole precursor. Deprotection and aromatization resulted in the first synthesis of desbromoceratamine A (55) and desmethyldesbromoceratamine A (60). An unanticipated addition of atmospheric oxygen was encountered during deprotection of the imidazole ring in the last step of the synthesis leading to C-11 oxygenated ceratamine analogues as byproducts. Evaluation of the synthetic ceratamines in a TG3 cell-based assay for mitotic arrest revealed that the C-14 and C-16 bromine substituents in ceratamine A (1) play a major role in the antimitotic potency of the natural product. The synthetic route to ceratamine analogues has provided sufficient quantities of desbromoceratamine A (55) for testing in mouse models of cancer.}, keywords = {6-PI-2-AZATRIENE ELECTROCYCLIZATION, AGELADINE-A, ANTIMITOTIC AGENTS, ARYL CHLORIDES, DIRECTED LITHIATION, HALIDES, IMIDAZOLE, PACLITAXEL, PALLADIUM-CATALYZED AMINATION, TAXOL}, isbn = {0022-3263}, url = {://000263004300005}, author = {Nodwell, M. and Pereira, A. and Riffell, J. L. and Zimmerman, C. and Patrick, B. O. and Roberge, M. and Andersen, R. J.} } @article {4690, title = {F-19 nuclear spin-rotation constant of yttrium monofluoride}, journal = {Journal of Molecular Spectroscopy}, volume = {198}, number = {1}, year = {1999}, note = {ISI Document Delivery No.: 246JGTimes Cited: 11Cited Reference Count: 22}, month = {Nov}, pages = {183-185}, type = {Article}, keywords = {HALIDES, LASER-ABLATION, MOLECULAR-BEAM, PUMP PROBE, SPECTROSCOPY, SPECTRUM, SRF, STATE}, isbn = {0022-2852}, url = {://000083160200019}, author = {Walker, K. A. and Gerry, M. C. L.} } @article {3785, title = {Density functional computations of the dipole moment derivatives for halogenated silanes}, journal = {Theochem-Journal of Molecular Structure}, volume = {363}, number = {1}, year = {1996}, note = {ISI Document Delivery No.: UH856Times Cited: 1Cited Reference Count: 49}, month = {Mar}, pages = {115-124}, type = {Article}, abstract = {Electric dipole moments for the equilibrium molecular structures and their derivatives along the symmetry coordinates of vibration were computed for SiH2F2, SiD2F2, SiH2Cl2, SiD2Cl2, SiH3F, SiD3F, SiH3Cl, SiD3Cl, SiHF3, SiDF3, SiHCl3, SiDCl3, SIFCl3, SiF3Cl, SiF4 and SiCl4 by means of the deMon density functional program (A. St-Amant and D. R. Salahub, Chem. Phys. Lett., 169 (1990) 387). Satisfactory agreement was found between the experimental and computed dipole moments for the equilibrium molecular structures. Perfect agreement was found between the rotational corrections to the dipole moment derivatives calculated by deMon and those obtained independently from the orthogonality relationships between the symmetry coordinates and the rotational coordinates. Derivatives of the dipole moments were transformed into the representation of the normal coordinates of vibration and the results were compared with the experimental data which are available on the infrared intensities of fundamental bands.}, keywords = {ABINITIO, density functional computations, DIPOLE MOMENT DERIVATIVES, GEOMETRIES, HALIDES, halogenated, METHANE, MICROWAVE-SPECTRA, MOLECULAR-STRUCTURES, QUADRUPOLE COUPLING-CONSTANTS, SILANES, SILYL, TRICHLOROSILANE, VIBRATIONAL-SPECTRA}, isbn = {0166-1280}, url = {://A1996UH85600010}, author = {Papousek, D. and Papouskova, Z. and Chong, D. P.} } @article {3264, title = {THE ONE-STEP SYNTHESIS OF CHIRAL AMINO PHOSPHINO FERROCENES}, journal = {Journal of Organometallic Chemistry}, volume = {492}, number = {2}, year = {1995}, note = {ISI Document Delivery No.: QV350Times Cited: 10Cited Reference Count: 24}, month = {May}, pages = {157-164}, type = {Article}, abstract = {Reaction of the chiral lithium reagent-2-lithio-(alpha-N,N-dimethyl)aminoethylbenzene with 1,1{\textquoteright}-ferrocenediylphenylphosphine gives chiral aminophosphinoferrocenes that contain both chiral carbon and phosphorus centres. Treatment of the ferroceno-phane with 2-lithio-N,N-dimethylaminomethylferrocene followed by hydrolysis gives the product ferrocenyl 2-(dimethylaminomethylferrocenyl) phenylphosphine as a pair of diastereomers. The single crystal structures of compound 3a PdCl2 and compound 4. PdCl2.2CH(2)Cl(2) have been determined. The compounds, 2-(ferrocenylphenylphosphino)-1-(alpha-N, N{\textquoteright}-dimethylaminoethylbenzene)ferrocene, 5 and 1-[2-(alpha-N,N{\textquoteright}-dimethyraminoethylbenzene)phenylphospphino]-1{\textquoteright}-diphenyl phosphinoferrocene, 6a, have also been prepared by minor modifications of the methodology developed.}, keywords = {<1>FERROCENOPHANES, ASYMMETRIC-SYNTHESIS, CATALYST, chirality, crystal structure, FERROCENE, GRIGNARD, HALIDES, HYDROGENATION, iron, METAL-COMPLEXES, ORGANIC, palladium, PHOSPHORUS, PLANAR CHIRALITY, REAGENTS, SECONDARY}, isbn = {0022-328X}, url = {://A1995QV35000005}, author = {Butler, I. R. and Cullen, W. R. and Rettig, S. J. and White, A. S. C.} }