[1]Ferrocenophanes with phosphorous and arsenic as the bridging atoms: Synthesis and some reactions. A new route to ferrocenyllithium reagents

Seyferth, Dietmar; Withers, Howard P.

doi:10.1016/s0022-328x(00)94410-3

Cited by 48 publications

(21 citation statements)

References 5 publications

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“…In particular, the I3c NMR chemical shift of the ips0 carbons of the cyclopentadienyl groups attached to the SiMe, bridge (36.9 ppm) showed the characteristic upfield shift compared to the other cyclopentadienyl carbons (22). This upfield shift is a well-established trend for strained, ring-tilted main group element-bridged [llferrocenophanes and is probably indicative of increased sp3 character for the ipso carbon bonded to the bridging silicon in comparison with ipso carbons in unbridged, substituted ferrocenes (22,23). Interestingly, all the other cyclopentadienyl I3c NMR resonances are located further downfield than the resonances reported for other symmetrically substituted, silicon-bridged [llferrocenophanes (e.g., 1).…”

mentioning

confidence: 61%

The synthesis and polymerization behaviour of silicon-bridged [1]- and [2]ferrocenophanes with sterically demanding trimethylsilyl substituents attached to the cyclopentadienyl rings

Peckham¹,

Foucher²,

Lough³

et al. 1995

Can. J. Chem.

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The silicon-bridged [llferrocenophane Fe(q-C,H3SiMe,),(SiMe2) (5) was synthesized via the reaction of Li,[Fe(q-C,H,SiMe,),].tmeda (tmeda = tetramethylethylenediamine) with Me2SiC1, in hexanes. The disilane-bridged [2]ferrocenophane Fe(q-C5H3SiMe,),(Si2Me4) (7) was prepared using a similar route from the disilane C1Me2SiSiMe2C1. Despite the presence of sterically demanding SiMe, substituents on the cyclopentadienyl rings, compound 5 was found to undergo thermal ring-opening polymerization at 170°C to produce very soluble, high molecular weight poly(ferrocenylsi1ane) 6 with Mw = 1.4 x lo5, M , = 8.4 x lo4.However, the [2]ferrocenophane 7 was found to be resistant to thermal ring-opening polymerization even at 350°C and decomposed above 380°C. A single-crystal X-ray diffraction study of 7 revealed that the steric interactions between the bulky SiMe, groups are relieved by a significant twisting of the disilane bridge with respect to the plane defined by the centroids of the cyclopentadienyl ligands and the metal atom. The angle between the planes of the cyclopentadienyl rings in 7 was found to be 5.4(6)", slightly greater than that in the non-silylated analogue Fe(q-C5H4),(Si2Me4) (4a) (4.19(2)"), and dramatically less than the corresponding tilt angle of the strained, polymerizable, silicon-bridged ,(SiMe2) (1) (20.8(5)"). The length of the Si-Si bond in 7 (2.342(3) A) was found to be close to the sum of the covalent radii (2.34 A). Crystals of 7 are monoclinic, space group C'lc, with a = 23.689(3) A, b = 11.174(1) A, c = 31.027(3) A, p = 109.16(1)", V = 7758(2) A3, and Z = 12.Key words: ring-opening polymerization, ferrocenophane, organometallic polymers.Rksumk : On a synthCtist le [I]ferroctnophane pontC par un silicium, Fe(q-C5H3SiMe3),(SiMe2) (5), par une rkaction du Li,[Fe(q-C5H3SiMe3),].tmeda (tmeda = tCtramtthyltthylknediamine) avec du Me2SiC12 dans de l'hexane. On a prCparC le [2]ferroctnophane pontt par deux silanes, Fe(q-C5H3SiMe3),(Si2Me4) (7). faisant appel ti une voie sernblable i partir du disilane C1Me2SiSiMe2C1. MalgrC la prksence sur les noyaux cyclopentadiCnyles de substituants SiMe, ayant une demande stCrique irnportante, on a trouvC que le compose 5 subit une polymCrisation therrnique par ouverture de cycle 2 170°C qui conduit au poly(ferrocCnylsi1ane) 6 trks soluble et de poids rnolCculaire ClevC avec Mw = 1,4 x lo5, M,, = 8,4 x lo4. Toutefois, on a trouvC que le[2]ferrocCnophane 7 est resistant une polyrnCrisation therrnique par ouverture de cycle, rn&rne a 350°C, et qu'il se dCcornpose i 380°C. Une ttude de diffraction des rayons X par un cristal unique du composC 7 rnontre que les interactions stCriques entre les groupes SiMe, sttriquernent encombrants sont apaisCes par une dtforrnation irnportante du pont disilane par rapport au plan dtfini par les centro~des des coordinats cyclopentadienyles et de l'atome de metal. On a trouvC que l'angle entre les plans des noyaux cyclopentadienyles du composC 7 est de 5,4(6)", ce qui est 1Cgkrernent supCrieur $ i la valeur de 4,19(2)" observke...

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confidence: 61%

The synthesis and polymerization behaviour of silicon-bridged [1]- and [2]ferrocenophanes with sterically demanding trimethylsilyl substituents attached to the cyclopentadienyl rings

Peckham¹,

Foucher²,

Lough³

et al. 1995

Can. J. Chem.

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“…Another specific approach, is the ring opening with phenyllithium of the strained 1-phenyl-1-phospha-[1]-ferrocenophane 6, which can be obtained from the corresponding 1,1′-dilithiated ferrocene 1 (Scheme 2) [22][23][24][25]. When this compound is now reacted with N,Ndimethylformamide, the corresponding phosphane ferrocenecarbaldehyde 8 is formed.…”

Section: Synthetic Routes Towards Chiral 11′-disubstituted Pn-ferromentioning

confidence: 99%

Ferrocene-derived P,N ligands: synthesis and application in enantioselective catalysis

Noël¹,

Eycken²

2013

Green Processing and Synthesis

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Due to their unique steric and electronic properties, air-stability and modular structure, chiral hybrid P,N-ferrocenyl ligands play a prominent role in the field of asymmetric catalysis. This report aims to give a concise introduction to the syntheses of chiral hybrid P,N-ferrocenyl ligands and presents an overview of their application in enantioselective catalysis. This review is of special interest to chemists working on ligand design and asymmetric catalysis, as well as to the broader organic and inorganic community.

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“…Thermal as well as nucleophile-assisted and cationic ROP can lead to polyferrocenylstannanes, emphasizing the reactivity of the C ipso ÀSn bond. [27,77] Unlike the more highly tilted boron-bridged [1] [6] and by Seyferth and Withers, Jr. [7] Most known derivatives to date bridged by phosphorus and arsenic have been prepared by the versatile reaction of dilithioferrocene(tmeda) with Group 15 organodihalides. [102] In some cases, the use of enantiomerically resolved dichloroorganophosphines has allowed access to chiral phosphorusbridged [1]ferrocenophanes.…”

Section: Ansa Complexesmentioning

confidence: 99%

“…[103] The similarities between phosphorus-bridged [1]ferrocenophanes are manifested in the narrow range of a angles (26.9-27.98). [6,7,23,[103][104][105][106][107] The single example of a structurally characterized arsa [1]ferrocenophane 30 (R 1 = CH(Me)NMe 2 ) contains more tilted cyclopentadienyl rings (a = 22.98) than expected given the larger covalent radius of arsenic. [23] The similarities between As-and P-bridged [1]ferrocenophanes are much more pronounced than between As-and Ge-bridged derivatives despite their nearly identical covalent radii (P 1.10 ; As 1.21 ; Ge 1.22 ).…”

Section: Ansa Complexesmentioning

confidence: 99%

“…[6][7][8] The unusual structures, reactivity, and potential utility of strained metallocenophanes and related species, such as metalloarenophanes (for example, 3; E = main-group element), have led to extensive recent developments in the area. The discovery in the early 1990s that strained ferrocenophanes undergo ROP to yield high-molecular-weight polyferrocenes [Eq.…”

Section: Introductionmentioning

confidence: 99%

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Strained Metallocenophanes and Related Organometallic Rings Containing π‐Hydrocarbon Ligands and Transition‐Metal Centers

2007

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The structures, bonding, and ring-opening reactions of strained cyclic carbon-based molecules form a key component of standard textbooks. In contrast, the study of strained organometallic molecules containing transition metals is a much more recent development. A wealth of recent research has revealed fascinating nuances in terms of structure, bonding, and reactivity. Building on initial work on strained ferrocenophanes, a broad range of strained organometallic rings composed of a variety of different metals, pi-hydrocarbon ligands, and bridging elements has now been developed. Such strained species can potentially undergo ring-opening reactions to functionalize surfaces and ring-opening polymerization to form easily processed metallopolymers with properties determined by the presence of the metal and spacer. This Review summarizes the current state of knowledge on the preparation, structural characterization, electronic structure, and reactivity of strained organometallic rings with pi-hydrocarbon ligands and d-block metals.

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[1]Ferrocenophanes with phosphorous and arsenic as the bridging atoms: Synthesis and some reactions. A new route to ferrocenyllithium reagents

Cited by 48 publications

References 5 publications

The synthesis and polymerization behaviour of silicon-bridged [1]- and [2]ferrocenophanes with sterically demanding trimethylsilyl substituents attached to the cyclopentadienyl rings

The synthesis and polymerization behaviour of silicon-bridged [1]- and [2]ferrocenophanes with sterically demanding trimethylsilyl substituents attached to the cyclopentadienyl rings

Ferrocene-derived P,N ligands: synthesis and application in enantioselective catalysis

Strained Metallocenophanes and Related Organometallic Rings Containing π‐Hydrocarbon Ligands and Transition‐Metal Centers

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