Alternative synthesis and crystal structure of a [2]boraferrocenophane

Braunschweig, Holger; Seeler, Fabian; Sigritz, Rainer

doi:10.1016/j.jorganchem.2007.02.008

Cited by 23 publications

(25 citation statements)

References 23 publications

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“…It is noteworthy, that the dilithiation of a large number of "non-iron" metallocenes and metalloarenes is well established by now and the aforementioned protocol for the synthesis of strained metallocenophanes and metalloarenophanes, respectively, is widely employed [8,9]. Subsequently, we reported an alternative synthesis of 5, its crystal structure, and initiated reactivity studies of this compound, revealing distinct, and to some extent surprising reactivity patterns [10]. Thus, in the presence of either boranes or diboranes, the formation of 1,1 0 -diborylferrocenes was observed [11].…”

Section: Introductionmentioning

confidence: 99%

Synthesis of a distanna [2]ferrocenophane and reactivity of [2]ferrocenophanes towards elemental sulfur and selenium

Bera

Braunschweig

Öechsner

et al. 2010

Journal of Organometallic Chemistry

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Section: Introductionmentioning

confidence: 99%

Synthesis of a distanna [2]ferrocenophane and reactivity of [2]ferrocenophanes towards elemental sulfur and selenium

Bera

Braunschweig

Öechsner

et al. 2010

Journal of Organometallic Chemistry

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“…The first example of this class of organometallic compound, the [2]boraferrocenophane 1, was prepared by Herberhold, Wrackmeyer and co-worker, [21] while the molecular structure along with an alternative synthesis was published by our group. [22] Subsequently, a series of [2]borametalloarenophanes has appeared. [23-28b] These ansa complexes show tilted molecular structures, thus featuring significant molecular strain.…”

mentioning

confidence: 99%

Unexpected Generation of Diastereomers by Double Diboration of a Dialkyne

Bauer

Braunschweig

Gruß

et al. 2011

Chemistry A European J

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During the last two decades, boron compounds have become established as versatile reagents in organic synthesis, and different methods have been developed for their preparation. Along with hydroboration, [1][2][3][4] transition-metalcatalyzed diboration [5] has become useful for the functionalization of unsaturated organic compounds. [6,7] This reaction is widely applicable to substrates such as alkynes [8,9] arynes, [10] alkenes, [11][12][13] carbenoids, [14,15] as well as diazo [16] and carbonyl compounds. [17][18][19][20] Although bis(catecholato)diborane(4) and bis(pinacolato)diborane(4) represent by far the most commonly employed diborane(4) species, the reaction is not restricted to their use. For instance, several diboranes(4) with interesting properties are derived from [2]borametalloarenophanes. The first example of this class of organometallic compound, the [2]boraferrocenophane 1, was prepared by Herberhold, Wrackmeyer and co-worker, [21] while the molecular structure along with an alternative synthesis was published by our group.[22] Subsequently, a series of [2]borametalloarenophanes has appeared. [23-28b] These ansa complexes show tilted molecular structures, thus featuring significant molecular strain. In 2006, we successfully exploited this ring strain in oxidative addition reactions of [2]borametalloarenophanes to low-valent platinum centers, affording[3]diboraplatinametalloarenophanes. In addition, we demonstrated the suitability of [2]borametalloarenophanes as diboranes(4) in the platinum-mediated diboration of alkynes to form [4]diboradicarbametalloarenophanes.[29] By expansion of this strategy, we also achieved the diboration of diazo compounds [16] and isocyanides.[30]Herein, we report on the two diastereomeric [4]diboradicarbaferrocenophanes 4 and 5, which were obtained by double diboration of the conjugated dialkyne 3 either by a platinum-mediated route employing the [2]boraferrocenophane 1 in the presence of [PtA C H T U N G T R E N N U N G (PEt 3 ) 3 ], or stoichiometrically by using the [3]diboraplatinaferrocenophane 2, directly (Scheme 1). In contrast to related transformations of monoalkynes, [29] monitoring the reaction progress by multinuclear NMR spectroscopy revealed the gradual disappearance of the starting materials, and the formation of two distinct compounds in benzene solution at elevated temperatures. Both species feature similar resonances in the 1 H, 11 B, and 13 C NMR spectra, which we rationalized by the generation of diastereomeric species. Complexes 4 and 5 were eventually isolated after workup as orange, moderately moisture-sensitive powders. The NMR spectroscopic data of both diastereomers are fully consistent with the presence of doubly bis(borylated), conjugated triene systems bearing two ferro-

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“…The most intriguing molecules are those of the monoboryl species. Tilt angles of 31.2 to 32.4°were observed for Me 2 NB(Cp) 2 Fe, (Me 3 Si) 2 NB(Cp) 2 Fe , tBu(Me 3 Si)NB(Cp) 2 Fe, iPr 2 NB(Cp) 2 Fe [31]. In case of 1,2-bis(dimethylaminodiboryl)- [2]ferrocenophane [32] the tilt angle is only 11.1°, and this angle is even further reduced to 2.6°in 24.…”

Section: Discussionmentioning

confidence: 98%

Synthesis and Structures of New Borylferrocenes, and Structures of, 2‐Chalcogeno‐bis(aminoboryl)[3]ferrocenophanes and 1,1′‐Tris(di‐methylaminoboryl))][3]ferrocenophane [1, 2]

Appel¹,

Nöth²

2010

Zeitschrift anorg allge chemie

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Abstract. The reaction of Br 2 BCpFeCp with (Me 3 Si) 2 S affords the hexacyclic tris(ferrocenyl)trithia-triborine (CpFeCp-BS) 3 , whereas the tris(ferrocenyl)boroxine is obtained from CpFeCpB(NMe 2 ) 2 and H 2 O via the isolated intermediate [CpFeCpBO) 3 ·HNMe 2 . In this compound there are two ferrocenyl units in trans-orientation and a third one is bonded to an O 2 BNHMe 2 unit with formation of a tetracoordinated boron atom (We use the symbol Cp here not only for the C 5 H 5 unit but also for C 5 H 4 or C 5 H 3 units). The structures of several bromo(dialkylamino)borylferrocenes and the 1,1'-bis[bromo(dialkylamino)-boryl]ferrocenes were determined. They show no Fe-B interaction.

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Alternative synthesis and crystal structure of a [2]boraferrocenophane

Cited by 23 publications

References 23 publications

Synthesis of a distanna [2]ferrocenophane and reactivity of [2]ferrocenophanes towards elemental sulfur and selenium

Synthesis of a distanna [2]ferrocenophane and reactivity of [2]ferrocenophanes towards elemental sulfur and selenium

Unexpected Generation of Diastereomers by Double Diboration of a Dialkyne

Synthesis and Structures of New Borylferrocenes, and Structures of, 2‐Chalcogeno‐bis(aminoboryl)[3]ferrocenophanes and 1,1′‐Tris(di‐methylaminoboryl))][3]ferrocenophane [1, 2]

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