The results of kinetic studies on the uncatalyzed [3,3]-sigmatropic rearrangement of 2-alkoxycarbonyl-substituted allyl vinyl ethers are reported. Apparently first reported by Gosteli in 1972, this variation of a Claisen rearrangement enjoyed a shadowy existence for three decades until its potential for the development of a catalytic asymmetric Claisen rearrangement was discovered. Inspired by this development, we have studied substituent and solvent rate effects, and we provide evidence that a chairlike transition state is highly favorable for the uncatalyzed Gosteli-Claisen rearrangement.
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{1,6}-Transannular catalytic asymmetric Gosteli-Claisen rearrangement.
Org Lett
August 2012
Fakultät Chemie, Technische Universität Dortmund, 44227 Dortmund, Germany.
The first uncatalyzed and [Cu(R-box)L(2)](SbF(6))(2)-catalyzed {1,6}-transannular Gosteli-Claisen rearrangement of cyclic 2-alkoxycarbonyl-substituted allyl vinyl ethers to afford medium- and large-sized carbacycles is disclosed.
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J Am Chem Soc
October 2011
Organisch-Chemisches Institut, Ruprecht-Karls Universität Heidelberg, 69120 Heidelberg, Germany.
The kinetics of the Cu(II)(bisoxazoline)-catalyzed diastereo- and enantioselective Gosteli-Claisen rearrangement of 2-alkoxycarbonyl-substituted allyl vinyl ethers has been investigated by enantioselective on-column reaction gas chromatography (ocRGC). Enantioselective ocRGC integrates (stereoselective) catalysis and enantioselective chromatography in a single microcapillary, which is installed in a GC-MS for direct analysis of conversion and selectivity. Thus, this technique allows direct differentiation of thermal and stereoselectively catalyzed reaction pathways and determination of activation parameters and selectivities of the individual reaction pathways starting from stereoisomeric reactants with high precision.
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Fakultät Chemie, Technische Universität Dortmund, 44227 Dortmund, Germany.
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Fakultät Chemie, Technische Universität Dortmund, 44227 Dortmund, Germany.
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Fakultät Chemie, Technische Universität Dortmund, Otto-Hahn-Strasse 6, 44221 Dortmund, Germany.
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