Spontaneous resolution versus formation of racemic crystals of indenylpotassium complexes
Journal article, 2013

During a study of stereochemically labile organometallic reagents, we found that crystallisation of [K(ind)(pmdta)](n) (ind = indenyl, pmdta = N,N,N',N '',N ''-pentamethyldiethylenetriamine) from tetrahydrofuran (THF) gave rise to three different crystalline phases depending on the concentration. The more concentrated solutions gave racemic crystals of the previously known coordination polymer [K(ind)(pmdta)](n), alpha-1. More dilute solutions gave crystals of a new phase, beta-1, which was found to undergo spontaneous resolution. From even more dilute solutions, we were able to isolate a chiral inclusion compound with THF, 2, which also undergoes spontaneous resolution. Crystals of beta-1 and 2 were enantiomerically pure, and since beta-1 is a reactive organometallic reagent, attempts were made to use the crystals in enantioselective synthesis. Reacting single crystals with N-chlorosuccinimide gave rise to chiral 1-chloroindene, but no enantiomeric excess was observed.

Organopotassium reagents

Concomitant polymorphism

Asymmetric synthesis

Spontaneous resolution


Susanne Olsson

University of Gothenburg

Anders Lennartsson

Chalmers, Chemical and Biological Engineering, Polymer Technology

Mikael Håkansson

University of Gothenburg

Journal of Organometallic Chemistry

0022-328X (ISSN)

Vol. 741-742 1 131-135

Subject Categories

Inorganic Chemistry



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