Abstract
A "conducted tour" migration keeps a mobile client on a profitable route even though an occasional side-step may seem attractive. A stereochemical manifestation of such a migration had been suggested by Donald J. Cram (1964), and we present now a different example that concerns the cis/trans stereoinversion of monomeric H2C=C(Li)-aryl compounds: Upon tetrahydrofuran (THF)-assisted heterolysis of the Li-C bond with formation of a solvent-separated ion pair (SSIP), the unchained mobile client Li+(THF)(4) is proposed to surmount the rim of the electronically fixed aryl group and to disdain the less encumbered pathways across the H2C=C region. This interpretation is based on knowledge from a previously published series of monomeric -arylalkenyllithiums in combination with two new members: 4-(-lithiovinyl)-2,2-dimethylbenz[f]indane (1) revealed both a barrier against -aryl rotation and a route-distinguishing retardation as compared with the corresponding migration-dependent cis/trans stereoinversion rate constant of 1-(-lithiovinyl)naphthalene (2). Monomeric and dimeric ground states of 1 and 2 and their microsolvation numbers were determined by using the recently developed primary and secondary NMR criteria.
| Dokumententyp: | Zeitschriftenartikel |
|---|---|
| Fakultät: | Chemie und Pharmazie > Department Chemie |
| Themengebiete: | 500 Naturwissenschaften und Mathematik > 540 Chemie |
| ISSN: | 0947-6539 |
| Sprache: | Englisch |
| Dokumenten ID: | 54300 |
| Datum der Veröffentlichung auf Open Access LMU: | 14. Jun. 2018, 09:55 |
| Letzte Änderungen: | 04. Nov. 2020, 13:33 |
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