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• 作者：Amritanshu Sinha ; Lourdes Pia H. Lopez ; Richard R. Schrock ; Adam S. Hock ; and Peter M&uuml ; ller
• 刊名：Organometallics
• 出版年：2006
• 出版时间：March 13, 2006
• 年：2006
• 卷：25
• 期：6
• 页码：1412 - 1423
• 全文大小：228K
• 年卷期：v.25,no.6(March 13, 2006)
• ISSN：1520-6041

文摘

The reaction between M(NAr)(CH-t-Bu)(CH₂-t-Bu)₂ (M = Mo, W, Ar = 2,6-i-Pr₂C₆H₃) and variousalcohols (1-adamantyl-OH, t-BuOH, ArOH, (CF₃)₂CHOH, (CF₃)₂MeCOH, CF₃Me₂COH, (CF₃)₃COH,C₆F₅OH) in pentane or toluene yields either complexes of the type M(NAr)(CH-t-Bu)(CH₂-t-Bu)(OR),through direct addition of ROH across a Mo-C bond, or complexes of the type M(NAr)(CH₂-t-Bu)₃(OR), through direct addition of ROH across a Mo=C bond. The trineopentyl species appear to be formedwhen the alcohol has a relatively low pK_a value. The outcome also can depend on whether the alcoholis employed neat or in benzene, and mixtures are observed in some circumstances. The conversion ofM(NAr)(CH₂-t-Bu)₃(OR) into M(NAr)(CH-t-Bu)(CH₂-t-Bu)(OR) was shown to be unimolecular in severalexamples. Preliminary experiments have shown that M(NAr)(CH-t-Bu)(CH₂-t-Bu)(OR) complexes aresurprisingly active catalysts for various metathesis reactions, although conversion is sometimes limitedby decomposition of intermediate alkylidenes to yield dimeric species that contain M=M bonds. In contrast,M(NAr)(CH-t-Bu)(CH₂-t-Bu)₂ species are virtually inactive for metathesis. X-ray structures are reportedfor Mo(NAr)(CH₂-t-Bu)₃(OC₆F₅), Mo(NAr)(CH-t-Bu)(CH₂-t-Bu)[OSi(O-t-Bu)₃], [Mo(NAr)(CH-t-Bu)(CH₂-t-Bu)(OC₆F₅)]₂, and Mo(NAr)(CH-t-Bu)(CH₂-t-Bu)(OC₆F₅)(PMe₃).