Synthese und reaktivität von übergangsmetall-substituierten phosphanen, arsanen und stibanen [1] LVII. Oxidation tertiärer und sekundärer Metallo-phosphane von eisen und wolfram mit dimethyldioxiran

Malisch, Wolfgang; Hindahl, Kathrin; Grün, Klaus; Adam, Waldemar; Prechtl, Frank; Sheldrick, William S.

doi:10.1016/0022-328x(95)05787-p

Cited by 9 publications

(3 citation statements)

References 35 publications

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“…The most noticeable feature in the IR spectrum of 5 in KBr are the absence of any ν(OH) band and the presence of two absorptions at 1105 and 1047 cm -1 due to the PO bond . In the 1 H NMR spectrum, the hydride ligands give rise to a double doublet with J (HP) values of 26.1 and 29.7 Hz, which are in agreement with the structure proposed for 5 in Scheme .…”

supporting

confidence: 82%

A Novel Method To Prepare Hydride−Phosphinito Complexes

et al. 2000

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The cyclopentadienyl complex Os(η 5 -C 5 H 5 )-Cl(P i Pr 3 ) 2 (1) reacts with diphenylphosphine to give the mixed-ligand compound Os(η 5 -C 5 H 5 )Cl(PHPh 2 )(P i Pr 3 ) (2). Treatment of 2 with TlPF 6 in humid acetone and in methanol affords the cationic dihydride complexes 4)), respectively. Similarly, the treatment of 2 with TlPF 6 in (CD 3 ) 2 CO containing D 2 O and in CD 3 OD gives the deuterated complexes [OsHD(η 5 -C 5 H 5 ){P(OR)Ph 2 }(P i -Pr 3 )]PF 6 (R ) D (3-d 2 ), CD 3 (4-d 4 )). The reaction of 3 with NaOCH 3 produces its deprotonation and the formation of the dihydride-phosphinito derivative OsH 2 -(η 5 -C 5 H 5 ){P(O)Ph 2 }(P i Pr 3 ) (5). Under the same conditions, the deprotonation of 4 yields OsH(η 5 -C 5 H 5 )-{P(OMe)Ph 2 }(P i Pr 3 ) ( 6) as a result of the extraction of one of the two hydrides. The treatment of 3-d 2 with NaOMe selectively affords OsHD(η 5 -C 5 H 5 ){P(O)Ph 2 }(P i -Pr 3 ) (5-d).

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confidence: 82%

A Novel Method To Prepare Hydride−Phosphinito Complexes

et al. 2000

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“…308 Oxidation of iron and tungsten phosphine complexes gives rise to the corresponding metal phosphine oxides. 309 Sulfurcontaining metal complexes are also oxidised by dioxiranes. 310 ± 312 Thus a new approach to the synthesis of chiral sulfoxides via diastereoselective oxidation by the dioxirane 1a of a prochiral thioether incorporated in a metal complex was reported.…”

Section: Oxidation Of Organometallic Compoundsmentioning

confidence: 99%

Dioxiranes: from oxidative transformations to chemiluminescence

Казаков¹,

Волошин²,

Казаков³

1999

Russ. Chem. Rev.

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“…The reactions are performed under neutral pH conditions, if necessary at subambient temperatures, and acetone is the only side product, which can be easily removed by distillation. In the meantime, for the three major reaction modes of dioxiranes 7 known in organic chemistry, examples have been documented in organometallic chemistry, namely epoxidation, hetereoatom oxidation, and X−H insertion . Additionally, for carbonyl complexes the CO ligand can be oxidized by dioxirane to carbon dioxide, which results either in the formation of oxo complexes or in the decomposition of the complex under liberation of organic ligands …”

Section: Introductionmentioning

confidence: 99%

Synthesis of Tris(pyrazolyl)borate-Stabilized Vinyl, Allyl, and Homoallyl Tungsten Oxides and Their Selective Oxyfunctionalization by Singlet Oxygen and Dioxirane

1996

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The synthesis of new tris(pyrazolyl)borato-substituted alkenyltungsten complexes and their oxyfunctionalization was investigated. The derivatives 2a−e of the title compounds were prepared in 40−70% yield by Grignard reaction of [Tp*W(O)2Cl] (1) [Tp* = hydridotris(3,5-dimethyl-1-pyrazolyl)borato] and subsequent treatment with molecular oxygen. These alkenyltungsten complexes, except the homoallyl complex 2b with a monosubstituted double bond, displayed a high reactivity toward singlet oxygen (1O2) to result in the corresponding allylic hydroperoxides by the Schenk ene reaction. While in the photooxygenation of the homoallyl complex 2a no special influence of the [Tp*W(O)2] fragment was observed, the allyl complexes 2c,d afforded stereoselectively the Z-configured products. Stereocontrol derives presumably from hyperconjugative stabilization by the W−C bond (β effect) of the perepoxide-like transition state. The allylic hydroperoxide, derived from the 1O2 ene reaction of the vinyl complex 2e, led by Hock-type cleavage to methacrolein and the tungstic acid derivative 9e. Upon photooxygenation in the presence of titanium tetraisopropoxide, only the homoallylic complex 2a underwent smoothly hydroxy-epoxidation. The other alkenyl complexes were sterically too hindered due to the bulky Tp* ligand. While the homoallyl and methallyl complexes 2a,d were quantitatively epoxidized by dimethyldioxirane (DMD), the vinyl complex 2e was again too sterically hindered because of the large [Tp*W(O)2] moiety, but its epoxide was obtained with m-chloroperbenzoic acid (mCPBA) as oxidant. In contrast, when equimolar amounts of methyl(trifluoromethyl)dioxirane (TFD) were used, the vinyl and methyl complexes 20e,f were regioselectively hydroxylated by C−H insertion into a pyrazolyl ring of the Tp* ligand. The present results demonstrate that the selective oxyfunctionalization of the alkenyltungsten complexes 2 by singlet oxygen and dioxiranes is controlled by electronic and steric factors of the [Tp*W(O)2] fragment.

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Synthese und reaktivität von übergangsmetall-substituierten phosphanen, arsanen und stibanen [1] LVII. Oxidation tertiärer und sekundärer Metallo-phosphane von eisen und wolfram mit dimethyldioxiran

Cited by 9 publications

References 35 publications

A Novel Method To Prepare Hydride−Phosphinito Complexes

A Novel Method To Prepare Hydride−Phosphinito Complexes

Dioxiranes: from oxidative transformations to chemiluminescence

Synthesis of Tris(pyrazolyl)borate-Stabilized Vinyl, Allyl, and Homoallyl Tungsten Oxides and Their Selective Oxyfunctionalization by Singlet Oxygen and Dioxirane

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