A Supramolecular Chiral Auxiliary Approach: “Remote Control” of Stereochemistry at a Hierarchically Assembled Dimeric Helicate |
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| Authors: | David Van?Craen Prof?Dr Markus Albrecht Prof?Dr Gerhard Raabe Fangfang Pan Prof?Dr Kari Rissanen |
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| Institution: | 1. Institut für Organische Chemie, RWTH Aachen, Aachen, Germany;2. Department of Chemistry, University of Jyv?skyl?, P.O. Box 35, Jyv?skyl?, Finland |
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| Abstract: | Dimeric hierarchically‐assembled titanium(IV) helicates are in solvent‐dependent equilibrium with the corresponding monomers. Statistically formed mixtures of such complexes bearing chiral stereocontrolling ligands and achiral diene‐substituted ligands show high diastereoselectivity and reasonable enantioselectivity in the Diels–Alder reaction with maleimides if the reaction proceeds with the dimer but not with the monomer. Thus, solvent dependent switching between the monomer and dimer enables on/off switching of the enantioselectivity. |
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| Keywords: | Diels– Alder reaction helicates lithium self-assembly titanium |
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