83742-19-2Relevant articles and documents
Synthesis and antiproliferative action of a novel series of maprotiline analogues
McNamara,Bright,Byrne,Cloonan,McCabe,Williams,Meegan
, p. 333 - 353 (2014/01/06)
The synthesis of a diverse library of compounds structurally related to maprotiline, a norepinephrine reuptake transporter (NET) selective antidepressant which has recently been identified as a novel in vitro antiproliferative agent against Burkitt's lymp
Selectivity for the methoxycarbonylation of ethylene versus CO-ethylene copolymerization with catalysts based on C4-bridged bidentate phosphines and phospholes
Doherty, Simon,Robins, Edward G.,Knight, Julian G.,Newman, Colin R.,Rhodes, Barrie,Champkin, Paul A.,Clegg, William
, p. 182 - 196 (2007/10/03)
The C4-bridged phospholes 11,12-bis(2,3,4,5-tetramethylphospholylmethyl)-9,10-dihydro-9,10-ethano- anthracene (cis, 4a; trans, 4b) and diphosphines 11,12-bis(diphenylphosphinomethyl)-9,10-dihydro-9,10-ethano-anthracene (cis, 5a; trans, 5b) and their corresponding palladium complexes [(P-P)PdCl2] (6a-d) have been prepared and characterized. Single-crystal X-ray analyses of 6a-d have been undertaken and they reveal that 4a and b and 5a and b coordinate in a bidentate manner forming seven-membered chelate rings with natural bite angles between 98.62 and 100.30°. The palladium-catalyzed carbonylation of ethylene has been studied using 4a and b and 5a and b. Catalyst mixtures generated from 4a and b, palladium acetate and methanesulfonic acid are selective for the copolymerization of ethylene with carbon monoxide, generating low molecular weight polymers. Surprisingly, the activity of catalyst systems based on cis-(4a) is markedly higher than that based on its trans-isomer, 4b. The marked influence of the nature of the four-carbon tether is highlighted by comparative catalyst testing with [{1,4-bis(2,3,4,5-tetramethylphospholyl)butane}Pd(OAc)2], which rapidly decomposes under the conditions used for copolymerization. In contrast, under identical conditions catalyst mixtures formed from 5a and b show a marked dependence of the selectivity on the stereochemistry of the ethano-anthracene tether, the former generating a low molecular weight copolymer while the latter generate mainly methyl propanoate. Interestingly, polyketone generated from catalysts based on bisphosphole 4a has a markedly higher average molecular weight than that formed using its diphenylphosphino counterpart, 5a.
Stereospecificity and concertedness of Retro-Diels-Alder fragmentation in some diester systems upon chemical ionization
Denekamp,Weisz,Mandelbaum
, p. 1028 - 1032 (2007/10/03)
Retro-Diels-Alder (RDA) fragmentation of cis- and trans-2,3-diethoxycarbonyl-5,6,7,8-dibenzobicyclo[2.2.2] octanes under isobutane and methane chemical ionization conditions is highly stereospecific, giving rise to protonated diethyl maleate and fumarate, respectively. This behaviour indicates a single-step concerted mechanism, analogous to the ground-state RDA process that occurs in neutral molecules in the condensed phase. The analogous dissociation is partially stereospecific in stereoisomeric endo-, exo- and trans-2,3-diethoxycarbonylbicyclo [2.2.1]heptanes and non-stereospecific in endo-, exo- and trans-2,3-diethoxycarbonyl-5,6-benzobicyclo [2.2.2]octanes, indicating the involvement of a stepwise mechanism in the latter two systems. The different behaviour of the above systems is explained in terms of the energy of the RDA fragmentation. The differentiation and quantitative estimates of protonated diethyl maleate and fumarate were obtained from collision-induced dissociation measurements.
