Reactivity of Silyl-Substituted Iron鈥揚latinum Hydride Complexes toward Unsaturated Molecules: 4. Insertion of Fluorinated Aromatic Alkynes into the Platinum鈥揌ydride Bond. Synthesis and Reactivity of H

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• 作者：Isabelle Jourdain ; Michael Knorr ; Carsten Strohmann ; Christian Unkelbach ; Sa煤l Rojo ; Patricia G贸mez-Iglesias ; Fernando Villafa帽e
• 刊名：Organometallics
• 出版年：2013
• 出版时间：October 14, 2013
• 年：2013
• 卷：32
• 期：19
• 页码：5343-5359
• 全文大小：842K
• 年卷期：v.32,no.19(October 14, 2013)
• ISSN：1520-6041

文摘

Insertion of p-FC₆H₄C鈮H, p-CF₃C₆H₄C鈮H, and m-CF₃C₆H₄C鈮H into the Pt鈥揌 bond of [(OC)₃Fe{Si(OMe)₃}(渭-dppm)Pt(H)(PPh₃)] (1a) yields first the 蟽-alkenyl complexes [(OC)₃Fe{渭-Si(OMe)₂(OMe)}(渭-dppm)Pt(ArC鈺怌H₂)] (2a, Ar = C₆H₄F-p; 2d, C₆H₄CF₃-p; 2e, C₆H₄CF₃-m), which react in a second step with the liberated PPh₃ ligand to afford the structurally characterized 渭-vinylidene complexes [(OC)₃Fe(渭-dppm){渭-C鈺怌(H)C₆H₄F-p}Pt(PPh₃)] (3a) and [(OC)₃Fe(渭-dppm){渭-C鈺怌(H)C₆H₄R}Pt(PPh₃)] (3d, R = p-CF₃; 3e, R = m-CF₃). In contrast, treatment of 1a with o-FC₆H₄C鈮H produces first [(OC)₃Fe{渭-Si(OMe)₂(OMe)}(渭-dppm)Pt(o-FC₆H₄C鈺怌H₂)] (2b), which evolves to the dimetallacyclopentenone complex [(OC)₂Fe(渭-dppm){渭-C(鈺怬)C(H)鈺怌(C₆H₄F-o)}Pt(PPh₃)] (4b鈥?/b>). The latter slowly rearranges to the structurally characterized thermodynamic isomer [(OC)₂Fe(渭-dppm){渭-C(鈺怬)C(C₆H₄F-o)鈺怌(H)}Pt(PPh₃)] (4b). Treatment of 1a with 2,4-F₂C₆H₃C鈮H produces via transient alkenyl complex 2c an isomeric mixture of [(OC)₃Fe(渭-dppm){渭-C鈺怌(H)C₆H₃F₂-2,4}Pt(PPh₃)] (3c), [(OC)₂Fe(渭-dppm){渭-C(鈺怬)C(H)鈺怌(C₆H₃F₂-2,4)}Pt(PPh₃)] (4c鈥?/b>), and [(OC)₂Fe(渭-dppm){渭-C(鈺怬)C(C₆H₃F₂-2,4)鈺怌(H)}Pt(PPh₃)] (4c). Alternatively, 4b,c and [(OC)₂Fe(渭-dppm){渭-C(鈺怬)C(Ar)鈺怌(H)}Pt(PPh₃)] (4a, Ar = C₆H₄F-p, 4d, Ar = C₆H₄CF₃-p) were obtained by reaction of [(OC)₃Fe(渭-dppm)(渭-C鈺怬)Pt(PPh₃)] with the respective terminal alkyne. Upon reaction of 1a, [(OC)₃Fe{Si(OMe)₃}(渭-dppa)Pt(H)(PPh₃)] (1b; dppa = bis(diphenylphosphino)amine), and [(OC)₃Fe{Si(OMe)₃}(渭-dppm)Pt(H)(PMePh₂)] (1c) with o-F₃CC₆H₄C鈮H, the dimetallacyclobutenes [(OC)₃Fe(渭-PPh₂XPPh₂){渭-C(C₆H₄CF₃-o)C鈺怌(H)}Pt(PPh₂R)] (5a, X = CH₂, R = Ph; 5b, X = NH, R = Ph; 5c, X = CH₂, R = Me) are formed as the sole products. Complexes 5 result also from the reaction of [(OC)₃Fe(渭-Ph₂PXPPh₂)(渭-C鈺怬)Pt(PPh₃)] (X = CH₂, NH) with o-trifluorophenylacetylene. NMR studies at variable temperatures reveal that dimetallacyclobutenes 5 are in equilibrium with dimetallacyclopentenones [(OC)₂Fe(渭-Ph₂PXPPh₂){渭-C(鈺怬)C(C₆H₄CF₃-o)鈺怌(H)}Pt(PPh₂R)] (4e, X = CH₂, R = Ph; 4f, X = NH, R = Ph; 4g, X = CH₂, R = Me). Addition of HBF₄ to 5 leads to formation of the Fe-蟽:渭₂-alkenyl salts [(OC)₃Fe(渭-Ph₂PXPPh₂){渭-C(C₆H₄CF₃-o)鈺怌H₂}Pt(PPh₃)][BF₄] (6a, X = CH₂; 6b, X = NH). Protonation of 4 gives the isomeric Pt-蟽:渭₂-alkenyl salts [(OC)₃Fe(渭-dppm){渭-CH₂鈺怌(Ar)}Pt(PPh₃)][BF₄] (7) together with small amounts of the Fe-蟽:渭₂-alkenyl salts [(OC)₃Fe(渭-dppm){渭-C(Ar)鈺怌H₂}Pt(PPh₃)][BF₄] (Ar = p-C₆H₄CF₃, p-C₆H₄F, 2,4-C₆H₃F₂). Protonation of the vinylidene complexes [(OC)₃Fe(渭-dppm){渭-C鈺怌(H)Ar}Pt(PPh₃)] (3; Ar = p-C₆H₄CF₃, Ph, p-C₆H₄CH₃) with HBF₄ occurs exclusively at the 伪-position of the vinylidene unit to produce a mixture of the isomeric 蟽-alkenyl salts cis-[(OC)₃Fe(渭-dppm){渭-C(H)鈺怌(H)Ar}Pt(PPh₃)][BF₄] (8-cis) and trans-[(OC)₃Fe(渭-dppm){渭-C(H)鈺怌(H)Ar}Pt(PPh₃)][BF₄] (8-trans).