Organische Metallkomplexe, XIX. Über die Struktur der Quecksilber (II)‐ Verbindungen mit Derivaten von β‐Diketonen

König, K.; Weiss, Willy; Musso, Hans

doi:10.1002/cber.19881210710

Cited by 11 publications

(1 citation statement)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Formation of complex 6 with the activation of the terminal methyl group is in contrast to the well-known activation of the central methylene group in β-diketones . Only one other example is known for such bond formation at the less acidic α-carbon atoms of β-diketones, i.e., the external α-carbon atom bound to a mercury atom, where, however, the internal carbon atom is bound to a bulky substituent . The bond length of Pt−C is 2.15 (2) Å in 4 and 2.114 (8) Å in 6 .…”

Section: Resultsmentioning

confidence: 96%

Synthesis of Ketonylplatinum(III) Dinuclear Complexes: Observation of the Competitive Radical vs Electrophilic Displacement in Pt(III)-Promoted C−H Bond Activation of Ketones

et al. 2001

View full text Add to dashboard Cite

New ketonylplatinum(III) dinuclear complexes [Pt(2)((CH(3))(3)CCONH)(2)(NH(3))(4)(CH(2)COPh)](NO(3))(3) (4), [Pt(2)((CH(3))(3)CCONH)(2)(NH(3))(4)(CH(CH(3))COC(2)H(5))](NO(3))(3) (5), and [Pt(2)((CH(3))(3)CCONH)(2)(NH(3))(4)(CH(2)COCH(2)COCH(3))](NO(3))(3) (6) were prepared by treatment of platinum blue complex [Pt(4)(NH(3))(8)((CH(3))(3)CCONH)(4)](NO(3))(5) (2) with acetophenone, 3-pentanone, and acetylacetone, respectively, in the presence of concentrated HNO(3). The structures of complexes 4 and 6 have been confirmed by X-ray diffraction analysis, which revealed that the C-H bonds of the methyl groups in acetophenone and acetylacetone have been cleaved and Pt(III)-C bonds are formed. Formation of diketonylplatinum(III) complex 6 provides a novel example of the C-H bond activation not at the central alpha-C-H but at the terminal methyl of acetylacetone. Reaction with butanone having unsymmetrical alpha-H atoms led to two types of ketonylplatinum(III) complexes [Pt(2)((CH(3))(3)CCONH)(2)(NH(3))(4)(CH(CH(3))COCH(3))](NO(3))(3) (7a) and [Pt(2)((CH(3))(3)CCONH)(2)(NH(3))(4)(CH(2)COCH(2)CH(3))](NO(3))(3) (7b) at a molar ratio of 1.7 to 1 corresponding to the C-H bond activation of methylene and methyl groups, respectively. Use of 3-methyl-2-butanone instead of butanone gave complex [Pt(2)((CH(3))(3)CCONH)(2)(NH(3))(4)(CH(2)COCH(CH(3))(2))](NO(3))(3) (8) as a sole product via C-H bond activation in the alpha-methyl group. The reactivity of the ketonylplatinum(III) dinuclear complexes toward nucleophiles, such as H(2)O and HNEt(2), was examined. The alpha-hydroxyl- and alpha-amino-substituted ketones were generated in the reactions of [Pt(2)((CH(3))(3)CCONH)(2)(NH(3))(4)(CH(2)COCH(3))](NO(3))(3) (1), 5, and a mixture of 7a and 7b with water and amine, which indicates that the carbon atom in the ketonyl group bound to the Pt(III) atom can receive a nucleophilic attack. The high electrophilicity of the ketonylplatinum(III) complexes can be accounted for by the high electron-withdrawing ability of the platinum(III) atom. A competition between the radical and electrophilic displacement pathways was observed directly in the C-H bond activation reaction with butanone giving complexes 7a and 7b. Addition of a radical trapping agent suppressed the radical pathway and gave complex 7b as the predominant product. On the contrary, 7a was formed as the main product when the reaction solution was irradiated by mercury lamp light. These results together with other mechanistic studies demonstrate that complex 7a was produced via a radical process, whereas complex 7b is produced via electrophilic displacement of a proton by the Pt(III) atom. The competitive processes were further observed in the reactions of platinum blue complex 2 with a mixture of acetone and 3-pentanone in the presence of HNO(3). The relative molar ratio of acetonyl complex 1 to pentanoyl complex 5 was 3 to 1 under room light, whereas formation of complex 5 was almost suppressed when the reaction was carried out in the dark with the addition of a radical trapping ag...

show abstract

Section: Resultsmentioning

confidence: 96%

Synthesis of Ketonylplatinum(III) Dinuclear Complexes: Observation of the Competitive Radical vs Electrophilic Displacement in Pt(III)-Promoted C−H Bond Activation of Ketones

et al. 2001

View full text Add to dashboard Cite

show abstract

Keto–enol equilibrium constants

Toullec

1990

PATAI'S Chemistry of Functional Groups

View full text Add to dashboard Cite

Organische Metallkomplexe, XX. Strukturen der Quecksilber (II)‐Verbindungen von Stickstoff‐ und Schwefel‐Analoga des 2,2,6,6‐Tetramethyl‐3,5‐heptandions

et al. 1988

View full text Add to dashboard Cite

Dipivaloylmethan (2,2,6,6‐Tetramethyl‐3,5‐heptandion, 4) bindet Hg(II) am mittleren Kohlenstoff zu 2. Ersetzt man einen Sauerstoff durch Stickstoff, so läßt sich ein cyclisches Trimeres 16 isolieren, in dem die Röntgenstrukturanalyse gleichfeste Bindungen von Hg(II) an C‐5 (2.10 Å) und N‐1 (2.08 Å) anzeigt; die Sauerstoffatome sind weiter entfernt (HgO 2.53 Å). Im Monothio‐Derivat 14 sind zwei Liganden über die Schwefelatome angenähert linear (174°) an Hg(II) gebunden (HgS 2.35 Å). Die Sauerstoffatome der Acylreste sind in beiden Fällen weiter entfernt (HgO in 16 2.53 Å, in 14 2.65 Å). Für den Hg‐Komplex des Liganden 9 mit Stickstoff und Schwefel wird die unsymmetrische Struktur 15 vorgeschlagen.

show abstract

Organische Metallkomplexe, XIX. Über die Struktur der Quecksilber (II)‐ Verbindungen mit Derivaten von β‐Diketonen

Cited by 11 publications

References 20 publications

Synthesis of Ketonylplatinum(III) Dinuclear Complexes: Observation of the Competitive Radical vs Electrophilic Displacement in Pt(III)-Promoted C−H Bond Activation of Ketones

Synthesis of Ketonylplatinum(III) Dinuclear Complexes: Observation of the Competitive Radical vs Electrophilic Displacement in Pt(III)-Promoted C−H Bond Activation of Ketones

Keto–enol equilibrium constants

Organische Metallkomplexe, XX. Strukturen der Quecksilber (II)‐Verbindungen von Stickstoff‐ und Schwefel‐Analoga des 2,2,6,6‐Tetramethyl‐3,5‐heptandions

Contact Info

Product

Resources

About