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Third-party-funded project

Strained Cycloallenes

Project management at the University of Würzburg:

Participating scientists:

The extremely short-lived intermediates cyclohexa-1,2,4-triene, 2,3-didehydro-1,2-dihydronaphthalene, and 1-methyl-1-azacyclohexa-2,3-diene(B-N)borane were generated by ß-elimination. Their existence was proven by interception in terms of cycloadditions with activated olefins such as furan and styrene. In the case of cyclohexa-1,2,4-triene and 2,3-didehydro-1,2-dihydronaphthalene, it could be shown that these intermediates are deprotonated by the strong base, necessary for the generation, to give the phenyl- and the 2-naphthylanion, respectively. The dimerisation of chiral allenes takes different stereochemical courses for pairs of enantiomers and pairs of homomers. Thus, a remarkable example for molecular recognition is provided by 1-phenylcycloocta-1,2-diene, as the racemate furnishes the virtually pure cis-dimer, whereas pure enantiomers give rise to the almost pure nonracemic trans-dimers.

Key words:

Projekt period: from 01.1999 to 12.2001

Funding institution:
DFG ,Granting date: 15.12.1998