694-70-2Relevant academic research and scientific papers
Tandem Ring-Opening–Ring-Closing Metathesis for Functional Metathesis Catalysts
Nagarkar, Amit A.,Yasir, Mohammad,Crochet, Aurelien,Fromm, Katharina M.,Kilbinger, Andreas F. M.
supporting information, p. 12343 - 12346 (2016/10/13)
Use of a tandem ring-opening–ring-closing metathesis (RORCM) strategy for the synthesis of functional metathesis catalysts is reported. Ring opening of 7-substituted norbornenes and subsequent ring-closing metathesis forming a thermodynamically stable 6-membered ring lead to a very efficient synthesis of new catalysts from commercially available Grubbs’ catalysts. Hydroxy functionalized Grubbs’ first- as well as third-generation catalysts have been synthesized. Mechanistic studies have been performed to elucidate the order of attack of the olefinic bonds. This strategy was also used to synthesize the ruthenium methylidene complex.
Ruthenium(II)-catalyzed [2+2] cycloadditions of anti 7-substituted norbornenes
Jordan, Robert W.,Le Marquand, Paul,Tam, William
, p. 80 - 86 (2008/09/17)
The ruthenium(II)-catalyzed [2+2] cycloadditions of anti 7-substituted norbornenes with an alkyne were investigated. The cycloadditions were found to proceed with a high degree of stereoselectivity, giving only the exo stereoisomers in moderate to good yields using an improved protocol. Comparative rate studies between a variety of anti 7-substituted norbornenes and an alkyne revealed that the reactivity of the alkene component decreases dramatically as the alkene becomes more electron deficient. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
Carbocation-forming reactions in ionic liquids
Creary, Xavier,Willis, Elizabeth D.,Gagnon, Madeleine
, p. 18114 - 18120 (2007/10/03)
A number of trifluoroacetates, mesylates, and triflates have been studied in ionic liquids. Several lines of evidence indicate that all of these substrates react via ionization to give carbocationic intermediates. For example, cumyl trifluoroacetates give mainly the elimination products, but the Hammett ρ+ value of -3.74 is consistent with a carbocationic process. The analogous exo-2-phenyl-endo-3-deutero-endo-bicyclo-[2.2.1]hept-2-yl trifluoroacetate gives an elimination where loss of the exo-hydrogen occurs from a cationic intermediate. 1-Adamantyl mesylate and 2-adamantyl triflate react to give simple substitution products derived from capture of 1- and 2-adamantyl carbocations by the residual water in the ionic liquid. The triflate derivative of pivaloin, trans-2-phenylcyclopropylcarbinyl mesylate, 2,2-dimethoxycyclobutyl triflate, the mesylate derivative of diethyl (phenylhydroxymethyl)-thiophosphonate, and Z-1-phenyl-5-trimethylsilyl-3-penten- 1-yl trifluoroacetate all give products derived carbocation rearrangements (kΔ processes), anti-7-Norbornenyl mesylate gives products with complete retention of configuration, indicative of involvement of the delocalized 7-norbornenyl cation. 1,6-Methano[10]annulen-11-yl triflate reacts in [BMIM][NTf2] to give 1,6-methano[10]annulen-11-ol, along with naphthalene, an oxidized product derived from loss of trifluoromethanesulfinate ion. Analogous loss of CF3SO2- can be seen in reaction of PhCH(CF3)OTf. Ionic liquids are therefore viable solvents for formation of carbocationic intermediates via kc and k Δ processes.
Influence of carbocation stability in the gas phase on solvolytic reactivity: Beyond bridgehead derivatives
Abboud, Jose-Luis M.,Alkorta, Ibon,Davalos, Juan Z.,Mueller, Paul,Quintanilla, Esther,Rossier, Jean-Claude
, p. 3786 - 3796 (2007/10/03)
The intrinsic gas-phase stability of bicyclic secondary carbocations has been determined by Dissociative Proton Attachment of chlorides and alcohols, respectively. From these data, Gibbs free energies for hydride transfer relative to 1-adamantyl (ΔrG°(8,exp)) are derived after application of appropriate leaving group corrections, and good agreement with theoretical values, (ΔrG°(8,comp)), calculated at the G2(MP2) or MP2/6-311G(d,p) level, is reached (Table 1). The relative rate constants for solvolysis (log(k/k0)) of the bicyclic secondary derivatives correlate with the stabilities of the respective carbocations in the same manner as tertiary bridgehead derivatives, but simple monoderivatives and acyclic derivatives solvolyze faster than predicted on the grounds of the ion stabilities. The corresponding stabilities of cyclopropyl- and benzyl-substituted carbocations have been obtained by a combination of experimental and computational data available in the literature with computational methods. Correlation of the rate constants for solvolysis vs ion stabilities for these compounds reveals a trend similar to that observed for bridgehead derivatives, but with much more scatter, which is attributed to nucleophilic solvent participation and/or nucleophilic solvation.
TETRAHYDROPYRANYL CYCLOPENTYL TETRAHYDROISOQUINOLINE MODULATORS OF CHEMOKINE RECEPTOR ACTIVITY
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Page/Page column 142-143, (2010/02/07)
The present invention is directed to compounds of the formula I: I(wherein R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, X, n and the dashed line are defined herein) which are useful as modulators of chemokine receptor activity. In particular, these compounds are useful as modulators of the chemokine receptor CCR-2.
Modulation Of ?-Facial Selectivities In Nucleophilic Additions to 7-Norbornenones
Mehta, Goverdhan,Khan, Faiz Ahmed
, p. 3065 - 3068 (2007/10/02)
The pronounced syn-face selectivity exhibited by 7-norbornenone in hydride reduction is dramatically altered (reversed) by the remote electron withdrawing substituents at the C2,C3-endo-position.Key Words: 7-Norbornenone, NaBH4 reduction, ?-face-selectivity.
PHOTOINDUCED ADDITION OF NUCLEOPHILES TO BICYCLOHEPTA-2,5-DIENE
Gassman, Paul G.,Olson, Kurt D.
, p. 19 - 22 (2007/10/02)
The 1-cyanonaphthalene photosensitized addition of water and methanol to the cation-radical of bicyclohepta-2,5-diene is described.
