The preparation and reaction chemistry of
![](/images/gifchars/beta2.gif)
-diketiminatoaluminum complexes aredescribed. (TTP)AlCl
2 (
1) (TTPH =2-(
p-tolylamino)-4-(
p-tolylimino)-2-pentene) isformedby the treatment of AlCl
3 with LiTTP. Sequentialalkylation of
1 with CH
3Li results intheformation of the mono- and dimethyl aluminum complexes (TTP)AlMeCl(
2) and (TTP)AlMe
2 (
3), respectively. Only monoalkylcomplexes are produced when more hinderedalkyllithium reagents are used. Compounds
2 and
3 are more conveniently prepared bytreating Al(CH
3)
3 with TTPH·HCl andTTPH, respectively. The more sterically hindered
![](/images/gifchars/beta2.gif)
-diketimine ligand2-((2,6-diisopropylphenyl)amino)-4-((2,6-diisopropylphenyl)imino)-2-pentene (DDPH) also reacts smoothly withAl(CH
3)
3 to yield(DDP)Al(CH
3)
2 (
4).Compound
3undergoes methyl abstraction reactions upon addition ofB(C
6F
5)
3 or AgOTf. Cationicspeciesformed from
3 andB(C
6F
5)
3 are unstable and decomposeto(TTP)Al(CH
3)(C
6F
5)and MeB(C
6F
5)
2. In contrast,(TTP)Al(CH
3)(OTf) (
6) isthermally stable, but the triflate group issurprisingly inert toward displacement by Lewis bases. Compounds
1,
3,
4, and
6werecrystallographically characterized. The structures all indicatethat the
![](/images/gifchars/beta2.gif)
-diketiminatobackbone is essentially planar. The pseudotetrahedral aluminumcenter is displaced fromthe plane formed by the ligand backbone in
4 by 0.72 Å.