Scandium, Yttrium, and Lanthanum Benzyl and Alkynyl Complexes with the N-(2-Pyrrolidin-1-ylethyl)-1,4-diazepan-6-amido Ligand: Synthesis, Characterization, and Z-Selective Catalytic Line
详细信息 查看全文
- 作者：Shaozhong Ge ; Auke Meetsma ; Bart Hessen
- 刊名：Organometallics
- 出版年：2009
- 出版时间：February 9, 2009
- 年：2009
- 卷：28
- 期：3
- 页码：719-726
- 全文大小：269K
- 年卷期：v.28,no.3(February 9, 2009)
- ISSN：1520-6041
文摘
1,4,6-Trimethyl-N-(2-pyrrolidin-1-ylethyl)-1,4-diazepan-6-amine (HL) reacts with M(CH2Ph)3(THF)3 to give the dibenzyl complexes (L)M(CH2Ph)2 (M = Sc, 1; M = Y, 2; M = La, 3). Compounds 1, 2, and 3 can be converted to their corresponding cationic monobenzyl species [(L)M(CH2Ph)]+ (M = Sc, Y and La) by reaction with [PhNMe2H][B(C6F5)4]. Reaction of (L)Sc(CH2Ph)2 with 2 equiv of phenylacetylene affords the monomeric dialkynyl complex (L)Sc(CCPh)2 (4), while reactions of (L)M(CH2Ph)2 (M = Y and La) give the dimeric dialkynyl complexes [(L)M(CCPh)(μ-CCPh)]2 (M = Y, 5; M = La, 6). The neutral complexes (2, 3, 5, and 6) and the cationic monobenzyl species [(L)M(CH2Ph)]+ (M = Y and La) are catalysts for the Z-selective linear head-to-head dimerization of phenylacetylenes. The cationic yttrium and the neutral lanthanum systems are the most effective catalysts in the series. The related scandium species show poor activity and selectivity.