Synthesis, Structure, and Reactivity of -Diketiminato Aluminum Complexes
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- 作者：Baixin Qian ; Donald L. Ward ; and Milton R. Smith ; III
- 刊名：Organometallics
- 出版年：1998
- 出版时间：July 6, 1998
- 年：1998
- 卷：17
- 期：14
- 页码：3070 - 3076
- 全文大小：133K
- 年卷期：v.17,no.14(July 6, 1998)
- ISSN：1520-6041
文摘
The preparation and reaction chemistry of 
-diketiminatoaluminum complexes aredescribed. (TTP)AlCl2 (1) (TTPH =2-(p-tolylamino)-4-(p-tolylimino)-2-pentene) isformedby the treatment of AlCl3 with LiTTP. Sequentialalkylation of 1 with CH3Li results intheformation of the mono- and dimethyl aluminum complexes (TTP)AlMeCl(2) and (TTP)AlMe2 (3), respectively. Only monoalkylcomplexes are produced when more hinderedalkyllithium reagents are used. Compounds 2 and3 are more conveniently prepared bytreating Al(CH3)3 with TTPH·HCl andTTPH, respectively. The more sterically hindered-diketimine ligand2-((2,6-diisopropylphenyl)amino)-4-((2,6-diisopropylphenyl)imino)-2-pentene (DDPH) also reacts smoothly withAl(CH3)3 to yield(DDP)Al(CH3)2 (4).Compound 3undergoes methyl abstraction reactions upon addition ofB(C6F5)3 or AgOTf. Cationicspeciesformed from 3 andB(C6F5)3 are unstable and decomposeto(TTP)Al(CH3)(C6F5)and MeB(C6F5)2. In contrast,(TTP)Al(CH3)(OTf) (6) isthermally stable, but the triflate group issurprisingly inert toward displacement by Lewis bases. Compounds1, 3, 4, and 6werecrystallographically characterized. The structures all indicatethat the -diketiminatobackbone is essentially planar. The pseudotetrahedral aluminumcenter is displaced fromthe plane formed by the ligand backbone in 4 by 0.72 Å.
-diketiminatoaluminum complexes aredescribed. (TTP)AlCl2 (1) (TTPH =2-(p-tolylamino)-4-(p-tolylimino)-2-pentene) isformedby the treatment of AlCl3 with LiTTP. Sequentialalkylation of 1 with CH3Li results intheformation of the mono- and dimethyl aluminum complexes (TTP)AlMeCl(2) and (TTP)AlMe2 (3), respectively. Only monoalkylcomplexes are produced when more hinderedalkyllithium reagents are used. Compounds 2 and3 are more conveniently prepared bytreating Al(CH3)3 with TTPH·HCl andTTPH, respectively. The more sterically hindered-diketimine ligand2-((2,6-diisopropylphenyl)amino)-4-((2,6-diisopropylphenyl)imino)-2-pentene (DDPH) also reacts smoothly withAl(CH3)3 to yield(DDP)Al(CH3)2 (4).Compound 3undergoes methyl abstraction reactions upon addition ofB(C6F5)3 or AgOTf. Cationicspeciesformed from 3 andB(C6F5)3 are unstable and decomposeto(TTP)Al(CH3)(C6F5)and MeB(C6F5)2. In contrast,(TTP)Al(CH3)(OTf) (6) isthermally stable, but the triflate group issurprisingly inert toward displacement by Lewis bases. Compounds1, 3, 4, and 6werecrystallographically characterized. The structures all indicatethat the -diketiminatobackbone is essentially planar. The pseudotetrahedral aluminumcenter is displaced fromthe plane formed by the ligand backbone in 4 by 0.72 Å.