Synthesis and crystal structure of diphenylcarbene(pentacarbonyl)tungsten(0)

Casey, Charles P.; Burkhardt, Terry J.; Bunnell, Charles A.; Calabrese, Joseph C.

doi:10.1021/ja00449a018

Cited by 200 publications

(49 citation statements)

References 18 publications

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“…For this purpose, a more complicated case is the crystal structure of [WA C H T U N G T R E N N U N G (CPh 2 )(CO) 5 ]. [21] This tungsten complex not only has a long W À CA C H T U N G T R E N N U N G (CPh 2 ) length of 2.14(2) and a W À C(CO trans to CPh 2 ) length of 2.04(2) , but also contains four CO ligands cis to the CPh 2 ligand with WÀC(CO) lengths of 1.98(2), 2.02(2), 2.02(2), and 2.03(3) .…”

Section: )}A C H T U N G T R E N N U N G (Thf)a C H T U N G T R E N Nmentioning

confidence: 99%

Trapping Reactive Metal–Carbene Complexes by a Bis‐Pocket Porphyrin: X‐ray Crystal Structures of RuCHCO₂Et and trans‐[Ru(CHR)(CO)] Species and Highly Selective Carbenoid Transfer Reactions

Deng

Chen

Huang

et al. 2009

Chemistry A European J

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The formation of CÀC bonds by a metal-catalyzed reaction of diazo compounds N 2 CR 1 R 2 with hydrocarbons, via putative metal-carbene intermediates, has a wide spectrum of applications in organic synthesis.[1] Identification of the reactive metal-carbene intermediates in these catalytic processes is of great importance for elucidating the reaction mechanisms. Since the isolation of (2À)) by Woo and co-workers [2] and [by Nishiyama and co-workers [3] from the reaction of diazo compounds with metal catalysts, a number of reactive metal-carbene complexes have been isolated or directly observed from such reactions.[2-4] Characterization of these reactive complexes by X-ray crystal analysis has been realized for the M=CR 1 R 2 (R 1 ¼ 6 H and R 2 ¼ 6 H) species.[4a,b,e,h-j] Recently, Simonneaux and co-workers structurally character- 5,10,15,20-tetraphenylporphyrinato(2À)), [5] an M=CHCO 2 R complex kinetically stabilized by a bulky R group.While N 2 CHCO 2 Et (EDA) has been used in numerous studies on metal-catalyzed carbenoid transfer reactions, particularly intermolecular cyclopropanation of alkenes,[1] the corresponding reactive M=CHCO 2 Et intermediates have sparsely been isolated, [2, 4c,d] in contrast to the report of a good number of reactive M=CR 1 R 2 (R 1 ¼ 6 H and R 2 ¼ 6 H) complexes.[6] To the best of our knowledge, only one M= CHCO 2 Et complex has been structurally characterized in the literature, that is, Werner and co-workers' carbene com-[7] which has not been reported to undergo carbenoid transfer with hydrocarbons. Given the effective shielding of the carbene center by bulky 2,6-tBu 2 -4-Me-C 6 H 2 in the structure of [Ru-[5] the X-ray crystal structure characterization of reactive M=CHCO 2 Et species, in which the Et group is too small to shield the carbene center, remains a challenge.A strategy for kinetically stabilizing reactive M= CHCO 2 Et complexes is to protect the carbene center with sterically encumbered auxiliary ligands. In this regard, we turned our attention to the bis-pocket porphyrin ligand 5,10,15,20-tetrakis(2,4,6-triphenylphenyl)porphyrinato(2À) (ttppp), which was first synthesized by Suslick and co-workers.[8] Metalloporphyrin-catalyzed alkene cyclopropanation with diazo compounds, including EDA, has received a considerable attention [9] since the pioneering work by Callot and Piechocki.

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Section: )}A C H T U N G T R E N N U N G (Thf)a C H T U N G T R E N Nmentioning

confidence: 99%

Trapping Reactive Metal–Carbene Complexes by a Bis‐Pocket Porphyrin: X‐ray Crystal Structures of RuCHCO₂Et and trans‐[Ru(CHR)(CO)] Species and Highly Selective Carbenoid Transfer Reactions

Deng

Chen

Huang

et al. 2009

Chemistry A European J

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“…Whilst it is quite obvious crystal structure analysis of compound 3b ( Figure 1, Table that compounds 3 are generated in an overall [3ϩ2] cyclo-1). The distance WϪC4 [2.276(4)] Å is longer than in addition as outlined above (Scheme 1), formation of com-non-heteroatom (carbene)tungsten complexes, such as pounds 4 seems to involve a more complicated reaction se-(CO) 5 WϭCPh 2 [2.15(1)] [12] and even longer than in pyrylquence (v.s. ).…”

mentioning

confidence: 96%

Mesoionic Pyrrolium Complexes and Dihydropyrroles by Cycloaddition of (Non-enolizable) Imines to an [(1-Alkynyl)carbene]tungsten Complex

Aumann¹,

Yu²,

Fröhlich³

et al. 1998

Eur. J. Inorg. Chem.

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Reaction of the [(1‐alkynyl)carbene]tungsten complex (CO)5W=C(OEt)C≡CPh (1a) with non‐enolizable imines, e.g. 9‐fluorenone imines 2 [NR = N(iPr), N(c‐C6H11)], affords novel mesoionic pyrrolium carbonyltungstates 3 (by [3+2] cycloaddition) together with dihydropyrroles 4 (by dichotomy of the C=N bond and subsequent insertion of the carbene carbon atom into an NC–H bond). Cross‐conjugated azametallatrienes 6 and pentacarbonyltungsten complexes 7 of the dihydropyrroles 4 have been identified to be precursors to compound 4. Compounds 3b, 4a, and 6a have been characterized by X‐ray crystal structure analyses.

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“…In a similar manner as described for the synthesis of 1a, the complex 3 reacts with the system Me 3 SiCF 3 /[Me 4 N]F in DME or THF at -30 to 25°C to form the stable bis(trifluoromethyl)-containing tungsten salt 6 in 70 % yield (Scheme 4). Whereas the diaryl analogues are stable up to -60°C, [20] we succeeded in the isolation of salt 6 and were able to characterise it by NMR spectroscopic techniques and elemental analysis. The tungsten compound 6 was obtained as a yellow solid which is stable in a dry argon atmosphere at -15°C for some days.…”

Section: Resultsmentioning

confidence: 99%

A General Route to Perfluoroalkyl‐ and Trifluorovinyl‐Substituted Fischer Carbene Complexes of Tungsten and Chromium – Syntheses, Characterisation and Structures

et al. 2011

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Synthesis and crystal structure of diphenylcarbene(pentacarbonyl)tungsten(0)

Cited by 200 publications

References 18 publications

Trapping Reactive Metal–Carbene Complexes by a Bis‐Pocket Porphyrin: X‐ray Crystal Structures of RuCHCO₂Et and trans‐[Ru(CHR)(CO)] Species and Highly Selective Carbenoid Transfer Reactions

Trapping Reactive Metal–Carbene Complexes by a Bis‐Pocket Porphyrin: X‐ray Crystal Structures of RuCHCO₂Et and trans‐[Ru(CHR)(CO)] Species and Highly Selective Carbenoid Transfer Reactions

Mesoionic Pyrrolium Complexes and Dihydropyrroles by Cycloaddition of (Non-enolizable) Imines to an [(1-Alkynyl)carbene]tungsten Complex

A General Route to Perfluoroalkyl‐ and Trifluorovinyl‐Substituted Fischer Carbene Complexes of Tungsten and Chromium – Syntheses, Characterisation and Structures

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Synthesis and crystal structure of diphenylcarbene(pentacarbonyl)tungsten(0)

Cited by 200 publications

References 18 publications

Trapping Reactive Metal–Carbene Complexes by a Bis‐Pocket Porphyrin: X‐ray Crystal Structures of RuCHCO2Et and trans‐[Ru(CHR)(CO)] Species and Highly Selective Carbenoid Transfer Reactions

Trapping Reactive Metal–Carbene Complexes by a Bis‐Pocket Porphyrin: X‐ray Crystal Structures of RuCHCO2Et and trans‐[Ru(CHR)(CO)] Species and Highly Selective Carbenoid Transfer Reactions

Mesoionic Pyrrolium Complexes and Dihydropyrroles by Cycloaddition of (Non-enolizable) Imines to an [(1-Alkynyl)carbene]tungsten Complex

A General Route to Perfluoroalkyl‐ and Trifluorovinyl‐Substituted Fischer Carbene Complexes of Tungsten and Chromium – Syntheses, Characterisation and Structures

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Trapping Reactive Metal–Carbene Complexes by a Bis‐Pocket Porphyrin: X‐ray Crystal Structures of RuCHCO₂Et and trans‐[Ru(CHR)(CO)] Species and Highly Selective Carbenoid Transfer Reactions

Trapping Reactive Metal–Carbene Complexes by a Bis‐Pocket Porphyrin: X‐ray Crystal Structures of RuCHCO₂Et and trans‐[Ru(CHR)(CO)] Species and Highly Selective Carbenoid Transfer Reactions