Synthesis and rearrangement of functionalized dispiro [3.0.3.3]Undecanes - a new entry to [3.3.3]Propellanes1

Fitjer, Lutz; Kanschik, Andreas; Majewski, M.

doi:10.1016/s0040-4039(00)95014-7

Cited by 19 publications

(7 citation statements)

References 17 publications

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“…This compound, hexakis(chlorodimethylsilyl)disilane (5a), can be prepared in three steps starting from tetrakis(trimethylsilyl)-silane by the formation of hypersilylpotassium developed by Marschner [9] [Equation (2)] and a subsequent oxidative dimerization of the hypersilanyl anion [Equation (3)]. (2) (3) FULL PAPER (4) The molecular structure of the formed hexakis(trimethylsilyl)disilane (4) has been reported previously [10,11] revealing an elongated central SiϪSi bond of 2.40 Å .…”

Section: Resultsmentioning

confidence: 99%

“…Hexakis(trimethylsilyl)disilane, Si 2 (SiMe 3 ) 6 (4): Si(SiMe 3 ) 4 was reacted in THF with KOtBu and the resulting KSi(Me 3 Si) 3 solution was treated with C 2 H 4 Br 2 as described in ref. [9] After removal of the solvent the product was a mixture of 4 and approximately 25% Si(SiMe 3 ) 4 . The two compounds were separated by sublimation in vacuo at 130°C for 6 h. The residue of the sublimation was almost pure 4 in 72% yield, which could be used without further purification.…”

Section: Methodsmentioning

confidence: 99%

“…It should be mentioned that carbon-based [3.3.3]propellanes have been known for some time [4,5] and even a naturally occurring sesquiterpene, modhephene (3b), [6,7] containing this tricyclic skeleton has been described. Molecular structures have been reported for modhephenediol (3c, 2,3-dihydroxy-2,4,4,8-tetramethyl [3.3.3]propellane, [6] ) and [3.3.3]-propellane-2,8,9-trione (3d).…”

Section: Introductionmentioning

confidence: 99%

“…[8] [a] Institut für Anorganische Chemie der TU Bergakademie Freiberg, Leipziger Str. 29, 09596 Freiberg, Germany [b] Institut für Chemie, Lehrstuhl Anorganische Chemie, TU Chemnitz, Straße der Nationen 62, 09111 Chemnitz, Germany compounds containing an Si(Si) 4 unit due to their incorporation into three five-membered rings. The molecular structures of 5a and 6a are reported revealing an elongated central Si−Si bond in 5a of 2.3865(11) Å and three different spatial orientations of the SiMe 2 Cl groups in each Si(SiMe 2 Cl) 3 unit.…”

Section: Introductionmentioning

confidence: 99%

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3,7,10-Trichalcogenaoctasila[3.3.3]propellanes

Herzog

Rheinwald

2001

Eur. J. Inorg. Chem.

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The reaction of hexakis(trimethylsilyl)disilane with acetyl chloride and aluminum chloride yields hexakis(chlorodimethylsilyl)disilane (5a) under carefully controlled reaction conditions. Treatment of 5a with either H 2 S/NEt 3 or Li 2 E (E = Se, Te) gives the dodecamethyl-3,7,10-trichalcogenaoctasila-[3.3.3]propellanes Si 2 (SiMe 2 ) 6 E 3 (6a E = S, 6b E = Se, 6c E = Te). The products have been characterized by multinuclear NMR spectroscopy ( 1 H, 13 C, 29 Si, 77 Se, 125 Te). The central silicon atoms are very deshielded in comparison with other

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Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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3,7,10-Trichalcogenaoctasila[3.3.3]propellanes

Herzog

Rheinwald

2001

Eur. J. Inorg. Chem.

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“…59 3.2.4 Fitjer and co-workers. As part of their works on the rearrangement of dispiroundecanes into triquinanes, [61][62][63] Fitjer et al also reported the synthesis of the natural product modhephene, starting from dispiroundecane 82 (Scheme 10), 21,22,64 which is accessible in eight steps from isopropylidenecyclobutane 22,64 and in nine steps from acetone. 22 Fitjer et al showed that when heated at 70 C under acidic conditions, 82 undergoes a series of rearrangements that yield two kinetic products: (AE)-modhephene ((AE)-1) and compound 86.…”

Section: Semi-synthesismentioning

confidence: 99%

Occurrence, synthesis and applications of natural and designed [3.3.3]propellanes

et al. 2020

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Ketene Cycloadditions

1994

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The reaction of ketene with itself was described almost simultaneously in 1908 by Chick and Wilsmore in England, and by Staudinger and Klever in Germany; priority for the discovery was attributed to Wilsmore by the German group. Ketene cycloaddition was an early example of a peculiar process, one that formed carbon–carbon bonds with ease, often without the need for solvent, catalyst, or high heat. Subsequent work by others was done in the shadow of Staudinger's exhaustive and rigorous study of all phases of ketene reactivity. Three factors led to a resurgence of interest in this reaction beginning in the 1960s. Haloketenes, which had previously eluded study, were found to have high reactivity, and the halogens could easily be removed after the reaction. The increasing sophistication of powerful analytical methods, particularly nuclear magnetic resonance spectroscopy, led to discovery of the interesting stereochemical aspects of this reaction. Finally, the new theory of orbital symmetry conservation provided a conceptual framework to rationalize these puzzling “no mechanism” reactions. This chapter is a review of cycloaddition reactions of ketenes. Here, a cycloaddition is defined as a reaction of a ketene with an unsaturated organic compound to give a cyclic product by a mechanism that, in principle, involves the almost simultaneous formation of two bonds between two reactants. While there is no concern here as to whether bond formation is concerted or stepwise, no other chemical process can take place between the formation of the first and second bond. Definition here involves both structural and mechanistic factors, and it is difficult to avoid a certain amount of arbitrariness. Products, such as dehydroacetic acid, which seem to us to arise by concatenation of ketene molecules followed by cyclization are excluded. These reactions, are more properly considered to arise from a series of ionic reactions, and the prediction of the eventual product does not take advantage of the special mechanistic features commonly associated with true cycloadditions. Additions to imines to give β‐lactams are numerous and will be covered in a separate review. The literature has been searched to the end of 1988. Many reviews devoted partially or exclusively to ketene cycloadditions have been published. Specific topics that have been reviewed include haloketenes, fluoroketenes, cyanoketenes, intramolecular cycloadditions, conjugated ketenes, and β‐lactam antibiotics. Ancillary topics pertinent to ketene cycloadditions that have been reviewed include cycloreversion reactions, ketene equivalents, which provide ketene functionality with olefin‐like reactivity especially in [4 + 2] reactions, application of frontier molecular orbital theory to cycloadditions, and a critical discussion of cycloadditions with polar intermediates. Applications of cyclobutanones in synthesis have also been reviewed.

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Synthesis and rearrangement of functionalized dispiro [3.0.3.3]Undecanes - a new entry to [3.3.3]Propellanes1

Cited by 19 publications

References 17 publications

3,7,10-Trichalcogenaoctasila[3.3.3]propellanes

3,7,10-Trichalcogenaoctasila[3.3.3]propellanes

Occurrence, synthesis and applications of natural and designed [3.3.3]propellanes

Ketene Cycloadditions

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