Structure-activity relationships for group 4 biaryl amidate complexes in catalytic hydroamination/cyclization of aminoalkenes
Gott, Andrew L., Clarke, Adam J., Clarkson, Guy J. and Scott, Peter. (2007) Structure-activity relationships for group 4 biaryl amidate complexes in catalytic hydroamination/cyclization of aminoalkenes. Organometallics, Vol.26 (No.7). pp. 1729-1737. ISSN 0276-7333Full text not available from this repository.
Official URL: http://dx.doi.org/10.1021/om061087l
Synthesis of bis(carboxamide) proligands derived from (R,S)-2,2'-diamino-6,6'dimethylbiphenyl was readily achieved by treatment of the amine with acid chlorides. Direct reaction with homoleptic alkyls of the group 4 metals cleanly yielded amidate complexes. These complexes were shown by single-crystal X-ray diffraction to be monomeric in the case of titanium and dimeric in the case of zirconium. The complexes formed do not yield well-defined cations upon reaction with standard borate/borane activators, and although some hydroamination catalysis was observed, it was not at a rate that is useful. In-situ treatment of Zr(NMe2)(4) with the proligands H2L1-4 yielded complexes of varying nuclearity depending on the steric bulk of the amide substituents, but in contrast to the metal alkyl series, mononuclear species are accessible; the mesityl derivative [(S)-(LZr)-Zr-4(NMe2)(2)] was found to be a highly enantioselective catalyst for the hydroamination/cyclization of 1-amino-2,2-dimethylpent-4-ene, with an enantiomeric excess of 91%.
|Item Type:||Journal Article|
|Subjects:||Q Science > QD Chemistry|
|Divisions:||Faculty of Science > Chemistry|
|Journal or Publication Title:||Organometallics|
|Publisher:||American Chemical Society|
|Official Date:||26 March 2007|
|Number of Pages:||9|
|Page Range:||pp. 1729-1737|
|Access rights to Published version:||Restricted or Subscription Access|
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