@article {2182, title = {Synthesis, characterisation, and in vitro evaluation of Pro(2)-Ile(3)-S-deoxo-amaninamide and Pro(2)-D-allo-Ile(3)-S-deoxo-amaninamide: Implications for structure-activity relationships in amanitin conformation and toxicity}, journal = {Chemistry-a European Journal}, volume = {14}, number = {11}, year = {2008}, note = {ISI Document Delivery No.: 291XITimes Cited: 0Cited Reference Count: 39May, Jonathan P. Fournier, Pierre Patrick, Brian O. Perrin, David M.}, pages = {3410-3417}, type = {Article}, abstract = {The amatoxins are a family of toxic bicyclic peptides that inhibit RNA polymerase II. Herein we discuss an improved synthesis of these compounds from easily obtainable amino acids by means of a solid-phase methodology. Interestingly, we obtained two products of the same mass following our final macrocyclisation, relating to a similar distribution of products described in some previous reports. One of these products was the desired amatoxin; Pro(2)-Ile(3)-S-deoxo-amaninamide 1b. The other compound, after thorough investigation, was confirmed to be the epimer Pro(2)-D-allo-Ile(3)-S-deoxo-amaninamide la, not an atropisomer structure as previously suggested in syntheses of related amanitin analogues. Crystallographic data of la confirms the presence of a beta II-turn, rather than a PI-turn common to the natural toxin and 1b. This difference explains the large variation in CD spectra, although it seems to have relatively little effect on the bioactivity in vitro. These data provide new insights into the bicyclic amatoxin structure.}, keywords = {ALPHA-AMANITIN, amatoxin, atropisomerism, circular dichroism, CRYSTALLINE STATE, CYCLIZATION, CYSTEINE SULFHYDRYL-GROUPS, EPIMERIZATION, MOLECULAR-STRUCTURE, PEPTIDES, RESOLUTION, RNA-POLYMERASE-II, SERIES, TOXIN BETA-AMANITIN, transcription}, isbn = {0947-6539}, url = {://000255230200020}, author = {May, J. P. and Fournier, P. and Patrick, B. O. and Perrin,David M.} } @article {2055, title = {A synthetic approach to the fusicoccane A-B ring fragment based on a Pauson-Khand cycloaddition/Norrish type 1 fragmentation}, journal = {Journal of Organic Chemistry}, volume = {73}, number = {17}, year = {2008}, note = {ISI Document Delivery No.: 344EDTimes Cited: 1Cited Reference Count: 88Dake, Gregory R. Fenster, Erik E. Patrick, Brian O.}, month = {Sep}, pages = {6711-6715}, type = {Article}, abstract = {A synthetic approach to the A-B ring system within the fusicoccane family of diterpenes is presented. Key steps in this approach are a diastereoselective Pauson-Khand reaction, a Norrish 1 photofragmentation, a Charette cyclopropanation, and a ring-closing metathesis process.}, keywords = {ALLYLIC ALCOHOLS, BICYCLIC SYSTEMS, CARBONYL-COMPOUNDS, CEROPLASTIN NUCLEUS, CLOSING METATHESIS, CYCLIZATION, DOLASTANE DITERPENES, ENYNE METATHESIS, NATURAL-PRODUCTS, NAZAROV, ORGANIC-SYNTHESIS}, isbn = {0022-3263}, url = {://000258908000030}, author = {Dake, G. R. and Fenster, E. E. and Patrick, B. O.} } @article {1332, title = {Bis(amidate) titanium precatalyst for the intermolecular hydroamination of allenes}, journal = {Inorganica Chimica Acta}, volume = {359}, number = {9}, year = {2006}, note = {ISI Document Delivery No.: 052YITimes Cited: 25Cited Reference Count: 64}, month = {Jun}, pages = {3097-3102}, type = {Article}, abstract = {A bis(amidate)-bis(amido) titanium complex (5) is an efficient precatalyst for the regioselective intermolecular hydroamination of substituted allenes. Arylamines react quickly with a 5 mol\% precatalyst loading at 90 degrees C to give the ketimine product, which can be reduced to give substituted amines. With precatalyst loading of 10 mol\% and temperatures of 120 degrees C alkyl amines can be used as viable substrates for the hydroamination of substituted allenes. (c) 2006 Elsevier B.V. All rights reserved.}, keywords = {ALKENES, allenes, amidate ligands, AMIDO COMPLEXES, CATALYST, CYCLIZATION, HYDROAMINATION, IMIDO COMPLEXES, INTRAMOLECULAR HYDROAMINATION, NITROGEN-HETEROCYCLES, ORGANOLANTHANIDE-CATALYZED HYDROAMINATION, precatalyst, TERMINAL ALKYNES, titanium complex, UNPROTECTED AMINO OLEFINS, VINYLARENES}, isbn = {0020-1693}, url = {://000238269600063}, author = {Ayinla, R. O. and Schafer, L. L.} } @article {1195, title = {High yielding synthesis of 3a-hydroxypyrrolo[2,3-b]indoline dipeptide methyl esters: Synthons for expedient introduction of the hydroxypyrroloindoline moiety into larger peptide-based natural products and for the creation of tryptathionine bridges}, journal = {Journal of Organic Chemistry}, volume = {70}, number = {21}, year = {2005}, note = {ISI Document Delivery No.: 971SRTimes Cited: 12Cited Reference Count: 33}, month = {Oct}, pages = {8424-8430}, type = {Article}, abstract = {This work describes a rapid and high yielding oxidation of 14 tryptophanylated amino acid methyl esters to the corresponding 3 alpha-hydroxypyrrolo[2,3-b]indoline (Hpi) amino acids with generally facile separation of syn-cis and anti-cis diastereomers. Structural X-ray diffraction data are presented for both diastereomers of Tr-Hpi-Gly-OMe, which allow for a putative assignment of the other 13 pairs of diastereomers reported herein, based on correlations with H-1 NMR chemical shifts. Selective and high yielding deprotection at either the N or C terminus is described, allowing the Hpi motif to be introduced efficiently into potential targets with minimal protecting group manipulation. Two tripeptides containing Hpi and cysteine were prepared and treated with acid in the Savige-Fontana reaction to produce a cyclic tryptathionine linkage, characteristic of both amatoxins and phallotoxins.}, keywords = {ANALOGS, ASYMMETRIC EPOXIDATION METHOD, CONFIGURATION, CONFORMATION, CYCLIZATION, CYSTEINE SULFHYDRYL-GROUPS, DERIVATIVES, HIMASTATIN, OXYGENATION, TRYPTOPHAN}, isbn = {0022-3263}, url = {://000232405500022}, author = {May, J. P. and Fournier, P. and Pellicelli, J. and Patrick, B. O. and Perrin,David M.} } @article {1070, title = {Nitrogenous educts through oxidative amidation of phenols: The bimolecular reaction}, journal = {Organic Letters}, volume = {7}, number = {2}, year = {2005}, note = {ISI Document Delivery No.: 887UFTimes Cited: 34Cited Reference Count: 29}, month = {Jan}, pages = {175-177}, type = {Article}, abstract = {The elusive oxidative amidation of phenols to 4-aza-substituted dienones in the bimolecular mode may be achieved by treatment with iodobenzene diacetate ("DIB") in a mixture of hexafluoro-2-propanol and acetonitrile.}, keywords = {(-)-TAN1251A, AMIDES, AMINATION, ARENES, CYCLIZATION, DERIVATIVES, FR901483, HYPERVALENT IODINE OXIDATION, N-ACYLNITRENIUM IONS, TYROSINE}, isbn = {1523-7060}, url = {://000226330300003}, author = {Canesi, S. and Bouchu, D. and Ciufolini,Marco A.} } @article {843, title = {Nucleophilic additions of lactam-derived enol triflates to aldehydes mediated by nickel(II) and chromium(II) salts}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {82}, number = {2}, year = {2004}, note = {ISI Document Delivery No.: 802BHTimes Cited: 5Cited Reference Count: 39}, month = {Feb}, pages = {139-144}, type = {Article}, abstract = {Enol trifluoromethanesulfonates (triflates) derived from N-protected lactams undergo nickel(II)-chloride- and chromium(II)-chloride-promoted carbonyl additions to aldehydes. The yields of this process range from 42\%-84\%.}, keywords = {BOND FORMATIONS, BREVETOXIN-B, carbonyl addition, CATALYSIS, chromium(II) chloride, CONSTRUCTION, CYCLIZATION, DERIVATIVES, DYNEMICIN-A, ENANTIOSELECTIVE, lactam-derived enol triflate, LEPADIN B, NI(II)/CR(II)-MEDIATED COUPLING REACTION, nickel(II) chloride, TOTAL-SYNTHESIS}, isbn = {0008-4042}, url = {://000220138500010}, author = {Easton, L. P. and Dake, G. R.} } @article {4766, title = {An investigation of the solid-state photochemistry of alpha-mesitylacetophenone derivatives: Asymmetric induction studies and crystal structure-reactivity relationships}, journal = {Tetrahedron}, volume = {56}, number = {36}, year = {2000}, note = {ISI Document Delivery No.: 351GHTimes Cited: 10Cited Reference Count: 24}, month = {Sep}, pages = {6739-6751}, type = {Article}, abstract = {The photochemical conversion of a series of alpha-mesitylacetophenone derivatives into 2-indanols via delta-hydrogen abstraction has been investigated in the solid state. A correlation between solid-state reactivity and crystal structure has been established for this type of reaction. For the seven compounds whose crystal structures were determined, the average value of d (C=O...H distance) and L (C=O...CH3 distance) were 2.77+/-0.04 Angstrom and 3.42+/-0.06 Angstrom, and the value of omega (delta-H out of plane angle), d (C=O...H angle) and a (C-H...O angle) were 59+/-2 degrees, 80+/-7 degrees and 123+/-3 degrees, respectively. These parameters depended mainly on the magnitude of the deviation of the carbonyl group from the fully bisecting position over the mesityl ring, which ranged from 9-14 degrees in the case of in the solid state reactive ketones and approached 0 degrees for the unreactive compounds. Asymmetric induction studies were carried out by providing the reactants with carboxylic acid substituents to which ionic chiral auxiliaries were attached through salt formation with optically active amines. Irradiation of the salts (13 in total) in the crystalline state gave enantiomeric excesses of up to 90\%. The crystal structures of three of the salts were determined and on this basis, the reasons for the selectivity in the crystalline state are discussed. (C) 2000 Elsevier Science Ltd. All rights reserved.}, keywords = {ABSTRACTION, ASYMMETRIC INDUCTION, CARBOXYLATE SALTS, CYCLIZATION, PHOTOCHEMISTRY, TRIPLETS, YANG PHOTOCYCLIZATION REACTION}, isbn = {0040-4020}, url = {://000089149100018}, author = {Cheung, E. and Rademacher, K. and Scheffer, J. R. and Trotter, J.} } @article {4766, title = {An investigation of the solid-state photochemistry of alpha-mesitylacetophenone derivatives: Asymmetric induction studies and crystal structure-reactivity relationships}, journal = {Tetrahedron}, volume = {56}, number = {36}, year = {2000}, note = {ISI Document Delivery No.: 351GHTimes Cited: 10Cited Reference Count: 24}, month = {Sep}, pages = {6739-6751}, type = {Article}, abstract = {The photochemical conversion of a series of alpha-mesitylacetophenone derivatives into 2-indanols via delta-hydrogen abstraction has been investigated in the solid state. A correlation between solid-state reactivity and crystal structure has been established for this type of reaction. For the seven compounds whose crystal structures were determined, the average value of d (C=O...H distance) and L (C=O...CH3 distance) were 2.77+/-0.04 Angstrom and 3.42+/-0.06 Angstrom, and the value of omega (delta-H out of plane angle), d (C=O...H angle) and a (C-H...O angle) were 59+/-2 degrees, 80+/-7 degrees and 123+/-3 degrees, respectively. These parameters depended mainly on the magnitude of the deviation of the carbonyl group from the fully bisecting position over the mesityl ring, which ranged from 9-14 degrees in the case of in the solid state reactive ketones and approached 0 degrees for the unreactive compounds. Asymmetric induction studies were carried out by providing the reactants with carboxylic acid substituents to which ionic chiral auxiliaries were attached through salt formation with optically active amines. Irradiation of the salts (13 in total) in the crystalline state gave enantiomeric excesses of up to 90\%. The crystal structures of three of the salts were determined and on this basis, the reasons for the selectivity in the crystalline state are discussed. (C) 2000 Elsevier Science Ltd. All rights reserved.}, keywords = {ABSTRACTION, ASYMMETRIC INDUCTION, CARBOXYLATE SALTS, CYCLIZATION, PHOTOCHEMISTRY, TRIPLETS, YANG PHOTOCYCLIZATION REACTION}, isbn = {0040-4020}, url = {://000089149100018}, author = {Cheung, E. and Rademacher, K. and Scheffer, J. R. and Trotter, J.} } @article {3663, title = {A remarkable multiple rearrangement process in the bromination of endo-3-bromo-4-methylcamphor: Intermediates for triterpenoid synthesis}, journal = {Tetrahedron}, volume = {52}, number = {47}, year = {1996}, note = {ISI Document Delivery No.: VT272Times Cited: 2Cited Reference Count: 36}, month = {Nov}, pages = {14661-14672}, type = {Article}, abstract = {The remarkable transformation of endo-3-bromo-4-methylcamphor (9) to endo-3,9-dibromo-4-(bromomethyl)camphor (11) forms the basis of a new approach to intermediates for the synthesis of lanostane triterpenoids, euphane triterpenoids and 14 alpha-methyl steroids. Copyright (C) 1996 Elsevier Science Ltd}, keywords = {4-METHYLCAMPHOR, CAMPHOR, CYCLIZATION, DERIVATIVES, ENANTIOSPECIFIC SYNTHESIS, NATURAL PRODUCT SYNTHESIS, ORGANIC-SYNTHESIS, ROUTE, STEROID-SYNTHESIS, SYNTHONS}, isbn = {0040-4020}, url = {://A1996VT27200003}, author = {Ferguson, C. G. and Money, T. and Pontillo, J. and Whitelaw, P. D. M. and Wong, M. K. C.} } @article {7120, title = {TERPENOIDS FROM THE SPONGE APLYSILLA-GLACIALIS AND SPECIMENS OF THE NUDIBRANCH CADLINA-LUTEOMARGINTA FOUND ON THE SPONGE}, journal = {Journal of Organic Chemistry}, volume = {56}, number = {1}, year = {1991}, note = {ISI Document Delivery No.: EQ979Times Cited: 21Cited Reference Count: 27}, month = {Jan}, pages = {42-47}, type = {Article}, abstract = {Four new rearranged and/or degraded {\textquoteright}{\textquoteright}spongian{\textquoteright}{\textquoteright} terpenoids and one new {\textquoteright}{\textquoteright}marginatane{\textquoteright}{\textquoteright} diterpenoid have been isolated from the marine sponge Aplysilla glacialis. The structure of cadlinolide A (3) was solved by X-ray diffraction analysis, and the structures of cadlinolide B (4), aplysillolide A (5), aplysillolide B (6), and marginatone (7) were determined by extensive spectroscopic analysis and chemical interconversions. Glaciolide (2), cadlinolide A (3), and tetrahydroaplysulphurin-1 (8) were isolated from skin extracts of specimens of the dorid nudibranch Cadlina luteomarginata found feeding on A. glacialis.}, keywords = {AMBLIOFURAN, CARBON SKELETON, CHROMODORIS-NORRISI, CONSTITUENTS, CYCLIZATION, DENDROCERATIDA, diterpenes, MARINE SPONGES, METABOLITES, OFFICINALIS}, isbn = {0022-3263}, url = {://A1991EQ97900010}, author = {Tischler, M. and Andersen, R. J. and Choudhary, M. I. and Clardy, J.} }