Please use this identifier to cite or link to this item:
Scopus Web of ScienceĀ® Altmetric
Type: Journal article
Title: Tertiary amine and N-heterocyclic carbene coordinated haloalanes-synthesis, structure, and application
Author: Alexander, Sean Geoffrey
Cole, M. L.
Forsyth, Craig M.
Citation: Chemistry-A European Journal, 2009; 15(36):9201-9214
Publisher: Wiley
Issue Date: 2009
ISSN: 0947-6539
School/Discipline: School of Chemistry and Physics : Chemistry
Statement of
Sean G. Alexander, Marcus L. Cole and Craig M. Forsyth
Abstract: The preparation of several tertiary amine and N-heterocyclic carbene coordinated chloro- and bromoalanes has been studied and routes to their gram-scale synthesis optimized. This provides a catalogue of well-characterized, thermally stable haloalanes for future application. All complexes have been investigated by spectroscopy (IR, NMR) and, where possible, singlecrystal X-ray diffraction structure determination. A particular focus of this article is the relative thermal stabilities of the complexes, which provides a useful handle for the aerobic stability of Group 13 hydride complexes. These thermal data have been elucidated in full and rationalized relative to one another on the basis of Lewis base donation, steric shielding, and relative inductive halide strengthening of the aluminum hydride bonds by halides. All of the four-coordinate complexes reported exist as distorted tetrahedra in the solid state with aluminum to N/Cdonor bonds that shorten with the increasing Lewis acidity of the aluminum Lewis acid. The five-coordinate complexes [AlBrH2ACHTUNGTRENUNG(Quin)2] and [AlBr2HACHTUNGTRENUNG( Quin)2] (Quin=quinuclidine) exist in a trigonal-bipyramidal geometry in the solid state with the amine donors situated in the apical positions. Five chlo- ACHTUNGTRENUNGroalanes; [AlClH2ACHTUNGTRENUNG(Quin)], [AlClH2- ACHTUNGTRENUNG(Quin)2], [AlCl2HACHTUNGTRENUNG(Quin)2], [AlClH2- ACHTUNGTRENUNG(IMes)], and [AlCl2HACHTUNGTRENUNG(IMes)] (IMes= 1,3-bis(2,4,6-trimethylphenyl)imidazol- 2-ylidene), the latter two of which are aerobically stable, have been applied to the hydroalumination of carbonyl and heterocycle substrates and their chemo-, regio-, and stereoselectivities compared to those of Group 13 hydride reagents cited in the literature. Overall, the reactivities of these species are comparable to non-halogenated alane complexes with the additional benefit of aerobic stability, non-pyrophoricity, and enhanced regioselectivity borne out of greater Lewis acidity.
DOI: 10.1002/chem.200900365
Appears in Collections:Chemistry publications

Files in This Item:
There are no files associated with this item.

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.