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Preparation of 6-aminocyclohepta-2,4-dien-1-one Derivatives via Tricarbonyltroponeiron
Published on: August 12, 2019
1-Titanacyclobuta-2,3-diene - an elusive four-membered cyclic allene
Fabian Reiß1, Melanie Reiß1, Jonas Bresien2
1Leibniz-Institut für Katalyse e.V. an der Universität Rostock , Albert-Einstein-Str. 29a , 18059 Rostock , Germany . Email: fabian.reiss@catalysis.de ;
Abstract:
The synthesis of an unusual 1-metalla-2,3-cyclobutadiene complex [rac-(ebthi)Ti(Me3SiC3SiMe3)] (rac-ebthi = rac-1,2-ethylene-1,1'-bis(η5-tetrahydroindenyl)), a formal metallacyclic analogue of a non-existent four-membered 1,2-cyclobutadiene, is described. By variation of the cyclopentadienyl ligand of the titanocene precursor it was possible to stabilise this highly exotic compound which selectively reacts with ketones and aldehydes to yield enynes by oxygen transfer to titanium. Analysis of the bonding and electronic structure of the metallacycle shows that the complex is best described as an unusual antiferromagnetically coupled biradicaloid system, possessing a formal Ti(iii) centre coordinated with a monoanionic radical ligand.
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