Synthesis, structure and oxidative addition reactions of triscyclopentadienyluranium(III) nitrile complexes

Adam, Raymond; Villiers, Claude; Ephritikhine, Michel; Lance, M.; Nierlich, Martine; Vigner, Julien

doi:10.1016/0022-328x(93)80193-f

Cited by 55 publications

(53 citation statements)

References 25 publications

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“…The shorter U1-O4 bond of 2.077(3) Å is indicative of stronger U-L electrostatic interaction in complex 3 than in 2 and is in agreement with the U-O distance reported for the only other known U(IV) diphenylmethoxide complex (2.071 Å). 19 In addition, the U1-O4-C70 angle of 178.4(3)°in 3 is close to linear, whereas the U1-O4-C70 angle of 2 is bent at an angle of 159.6(3)°.…”

Section: Bumentioning

confidence: 96%

“…[15][16][17][18] Despite successes with the structural isolation of fluorenone ketyls, those of benzophenone ketyls are still sought after because they have shown to be much more reactive. 7,9,12,13 Attempts to isolate metal benzophenone ketyl radicals have often resulted in hydrogen abstraction to form metal alkoxides, 17,19 insertions into M-L bonds, [20][21][22][23][24][25][26][27][28] pinacolate complexes. 17,[29][30][31][32][33] To date, the isolation and structural characterization of benzophenone ketyl radical complexes are limited to complexes of alkali/alkaline earth and samarium metals.…”

Section: Introductionmentioning

confidence: 99%

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Structural and Spectroscopic Characterization of a Charge-Separated Uranium Benzophenone Ketyl Radical Complex

et al. 2008

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The reaction of [((t-Bu)ArO) 3tacn)U (III)] ( 1) with 4,4'-di- tert-butylbenzophenone affords a unique isolable U(IV) ketyl radical species [((t-Bu)ArO) 3tacn)U (IV)(OC* (t-Bu)Ph 2)] (2) supported by XRD data, magnetization measurements, and DFT calculations. Isolation and full characterization of the corresponding diphenyl methoxide complex [((t-Bu)ArO) 3tacn)U (IV)(OCH ( t-Bu )Ph 2)] (3) is also presented. The one-electron reduction of benzophenone by [((Ad)ArO) 3tacn)U (III)] (4) leads to a purple U(IV) ketyl radical intermediate [((Ad)ArO) 3tacn)U (IV)(OC*Ph 2)] (5). This species is highly reactive, and attempts at isolation were unsuccessful and resulted in methoxide complex [((Ad)ArO) 3tacn)U (IV)(OCHPh 2)] (6) from H abstraction and dinuclear para-coupled complex [((Ad)ArO) 3tacn)U (IV)(OCPhPhCPh 2O)U (IV)((Ad)ArO) 3tacn)] (7).

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Section: Bumentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

Structural and Spectroscopic Characterization of a Charge-Separated Uranium Benzophenone Ketyl Radical Complex

et al. 2008

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“…[2][3][4][5][6][7][8][9][10] Furthermore, one example each of Mo, [11] Co, [12] and U [13] and two examples of Cu [14,15] were reported. They mainly involve Group 10 transition-metal triads.…”

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confidence: 99%

Iron‐Complex‐Catalyzed CC Bond Cleavage of Organonitriles: Catalytic Metathesis Reaction between HSi and RCN Bonds to Afford RH and SiCN Bonds

Nakazawa

Itazaki

Kamata

et al. 2007

Chemistry An Asian Journal

106

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The first example of the catalytic C-CN bond cleavage of acetonitrile as well as Si-CN bond formation have been achieved in the photoreaction of MeCN with Et3SiH promoted by [Cp(CO)2FeMe]. This catalytic system is applicable to other organonitriles. Several iron complexes [(eta(5)-C5R5)(CO)2FeR'] (R5 = H5, H4Me, Me5, H4SiMe3, H4I, H4P(O)(OMe)2; R' = SiMe3, CH2Ph, Me, Cl, I) were examined as catalyst, and [Cp(CO)2FeMe] was found to be the best precursor. A catalytic reaction cycle was proposed, which involves oxidative addition of Et3SiH to [Cp(CO)FeMe], reductive elimination of CH4 from [Cp(CO)FeMe(H)(SiEt3)], coordination of RCN to [Cp(CO)Fe(SiEt3)], silyl migration from Fe to N in the coordinated RCN, and dissociation of Et3SiNC from Fe. The reaction with MeCN of [Cp(CO)Fe(py)(SiEt3)], which was newly prepared and determined by X-ray analysis, and the reaction of Et3SiH with MeCN in the presence of a catalytic amount of [Cp(CO)Fe(py)(SiEt3)] showed that the 16-electron species [Cp(CO)Fe(SiEt3)] is the active species in the catalytic cycle (TON up to 251).

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“…Two NCH 3 resonances were observed at room temperature in 1 H and 13 C NMR, reflecting that the C2-N1 bond does not rotate freely at room temperature. Catalytic N-CN bond cleavage of cyanamides has been attempted.…”

Section: N-cn Bond Cleavage Of Cyanamidesmentioning

confidence: 99%

“…They mainly involve Group 10 transition metal triads [2][3][4][5][6][7][8][9][10]. In addition, one example for Mo [11], Co [12], U [13], and two examples of Cu [14,15] have been reported. These reactions show stoichiometric C-C bond cleavage.…”

Section: Introductionmentioning

confidence: 99%

Strong bond cleavage promoted by silyl group migration in a coordination sphere

Nakazawa

2011

WIT Transactions on Ecology and the Environment

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C-CN bond cleavage in organonitriles was attained in the photoreaction with HSiEt 3 in the presence of a catalytic amount of ( 5 -C 5 H 5 )Fe(CO) 2 Me. The reaction sequence was proposed, where silyl migration from Fe to N in the coordinating nitrile is a key step. DFT calculations proposed a silyl migration with small activation energy of 4.0 kcal/mol and subsequent C-CN bond cleavage on the Fe coordination sphere. N-CN bond cleavage in cyanamide (R 2 NCN) was also attained by a transition metal catalyst. A catalytic cycle was proposed where a silyl migration from a transition metal to the nitrile nitrogen is involved. An N-silylated  2 -amidino complex was isolated, which was shown to be an intermediate in the catalytic pathway.

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Synthesis, structure and oxidative addition reactions of triscyclopentadienyluranium(III) nitrile complexes

Cited by 55 publications

References 25 publications

Structural and Spectroscopic Characterization of a Charge-Separated Uranium Benzophenone Ketyl Radical Complex

Structural and Spectroscopic Characterization of a Charge-Separated Uranium Benzophenone Ketyl Radical Complex

Iron‐Complex‐Catalyzed CC Bond Cleavage of Organonitriles: Catalytic Metathesis Reaction between HSi and RCN Bonds to Afford RH and SiCN Bonds

Strong bond cleavage promoted by silyl group migration in a coordination sphere

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