- Selective alkylation and Suzuki coupling as an efficient strategy for introducing functional anchors to the ethylene-bis(indenyl) ligand
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Chiral ansa-ethylene-bis(indenyl)-metal complexes, EBI-MX2, are useful pre-catalysts for a wide variety of reactions, including hydrogenations, hydrosilylations, and polymerization reactions. In order to immobilize these complexes onto heterogeneous supports, a new methodology was developed to introduce functional anchors to the ethylene-bis(indenyl) ligand, EBI. This was accomplished by selective alkylation of indene to form toluene-4-sulfonic acid 2-(3H-inden-1-yl)-ethyl ester, which was then used to alkylate 6-bromoindene. The selective introduction of an aryl bromide then undergoes coupling reactions with aryl borates via the Suzuki coupling to efficiently introduce an alkenyl or alcohol, functional anchor in a simple four step synthesis.
- Panarello, Anthony P.,Vassylyev, Oleksiy,Khinast, Johannes G.
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p. 1353 - 1356
(2007/10/03)
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- Solvolysis Mechanism of Indan-2-yl Arenesulfonates
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The solvolysis rates of 5-(Y)-substituted indan-2-yl (Z)-benzenesulfonates were determined in a variety of protic solvents at 45.0, 55.0 and 65.0 deg C.Application of an extended Grunwald-Winstein equation indicates that kinetic responses to both solvent ionizing power, YOTs, and solvent nucleophilicity, NOTs, are relatively low but increase in parallel with increasing leaving ability, m = 0.39-0.46 and I=0.32-0.41 for Z=p-Me p-NO2.The magnitude of cross-interaction constant, ρYZ, is also relatively small (0.16-0.32), which is, however, much more dependent on the nucleophilicity rather than the ionizing power of the solvent.These are consistent with the typical SN2 mechanism proceeding through a transition state in which solvent participates in both bond-making and -breaking processes.
- Lee, Ikchoon,Lee, Young Sook,Lee, Bon-Su,Lee, Hai Whang
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p. 1441 - 1445
(2007/10/02)
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