Beryllium Dichloride: Efficient promoter for the Addition of Organolithiums and Organomagnesiums to Cyclohexen-2-one

Krief, Alain; Vos, M. J. De; Lombart, Stephane De; Bosret, J.; Couty, François

doi:10.1016/s0040-4039(97)01416-0

Cited by 10 publications

(4 citation statements)

References 14 publications

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“…Bulky allyl ligands12 and those with pendant groups13 have been used to suppress oligomerization and enhance solubility in a wide range of metal complexes. The chance to use such ligands in organoberyllium chemistry is appealing, especially as the reactivity of alkyl and aryl beryllium chlorides may depend on their state of aggregation in solution 14. Herein we report the synthesis, solution behavior, and crystal structure of a base adduct of bis(1,3‐trimethylsilylallyl)beryllium.…”

Section: Methodsmentioning

confidence: 99%

Hybrid Porous Materials with High Surface Area Derived from Bromophenylethenyl‐Functionalized Cubic Siloxane‐Based Building Units

Chaikittisilp

Sugawara

Shimojima

et al. 2010

Chemistry A European J

117

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Sonogashira cross-coupling of bromophenylethenyl-terminated cubic, double four-ring, siloxane cages with di-/triethynyl compounds results in microporous poly(ethynylene aryleneethenylene silsesquioxane) networks, simply termed as polyorganosiloxane networks (PSNs). In comparison with porous organic polymers reported previously, these PSNs show relatively high surface area and comparable thermal stability. Their apparent BET specific surface areas vary in the range of 850-1040 m(2) g(-1) depending on the length and the connectable sites of the ethynyl compounds. Analyses of pore size distribution revealed bimodal micropores with relatively narrow distribution. The degree of cross-linking affects the degree of cleavage of the siloxane bonds, and this suggests that partial cleavage of the siloxane cages is mainly a result of cage distortion. Hydrogen adsorption was performed to evaluate potential of the PSNs as hydrogen storage media. Uptakes of up to 1.19 wt% at 77 K and 760 Torr and initial isosteric heats of adsorption as high as 8.0 kJ mol(-1) were observed. These materials have been obtained by a combination of structural, synthetic organic, and materials chemistry, which can exploited to synthesize porous hybrid materials with specifically designed structures and functions.

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Section: Methodsmentioning

confidence: 99%

Hybrid Porous Materials with High Surface Area Derived from Bromophenylethenyl‐Functionalized Cubic Siloxane‐Based Building Units

Chaikittisilp

Sugawara

Shimojima

et al. 2010

Chemistry A European J

117

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“…In addition, crowded ketones such as 2,6-dimethylcyclohexanone provided only traces of addition product, independent of the conditions used. Finally, attempts to conduct transmetalation reactions by using derivatives of elements that are more electropositive than Si or Sn (e.g., ZnCl 2 , ZnBr 2 , Zn(OTf) 2 , B(OMe) 3 , CeCl 3 , CeBr 3 , ClTi(O i- Pr) 3 , Cl 2 Ti(O i -Pr) 2 , and BeCl 2 ) under various conditions have failed, to date, to afford any synthetically useful results.…”

Section: Resultsmentioning

confidence: 99%

1-Bromo-1-lithioethene: A Practical Reagent in Organic Synthesis

Novikov

Sampson

2005

J. Org. Chem.

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[reaction: see text] A reliable preparative scale synthesis of 1-bromo-1-lithioethene is reported. This reagent undergoes clean 1,2-addition with a range of aldehydes and ketones at -110 degrees C to afford the corresponding 2-bromo-1-alken-3-ols in moderate to excellent yield. Trapping with other electrophiles (acylsilanes, chlorosilanes, tributyltin chloride, iodine) cleanly provides practically useful yields of various 1-substituted 1-bromoethene products. Unexpectedly high diastereoselectivities were observed during the addition of 1-bromo-1-lithioethene to alpha-siloxy aldehydes (typically 10:1, Felkin-Ahn control) and protected ketopyranose and ketofuranose sugars (> or = 10:1, addition from the less-hindered face). The title organolithium reagent possesses relatively low basicity at low temperature, and is compatible with a variety of common protecting groups. We believe that these unusual properties of 1-bromo-1-lithioethene may originate from the specific crystalline structure of the reagent in which lithium is coordinatively saturated and thus unavailable for chelation.

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“…The chance to use such ligands in organoberyllium chemistry is appealing, especially as the reactivity of alkyl and aryl beryllium chlorides may depend on their state of aggregation in solution. [14] Herein we report the synthesis, solution behavior, and crystal structure of a base adduct of bis(1,3-trimethylsilylallyl)beryllium. We also describe computational investigations of the preferred bonding mode of allyl ligands to beryllium (that is, s-bound (h 1 ) or p-bound (h 3 )).…”

mentioning

confidence: 99%

“…Evidence for the persistence of a s-bonded structure in solution is provided by IR and beryllium NMR spectroscopy (14), O-Be-C4 112.91 (14). measurements.…”

mentioning

confidence: 99%

Bis(1,3‐trimethylsilylallyl)beryllium

2010

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Shape‐shifter: The beryllium allyl complex [Be{1,3‐(SiMe3)2C3H3}2(Et2O)] (see picture) has been synthesized and its X‐ray structure determined. Although the allyl ligands are σ bonded, the molecule is fluxional in solution, and it engages in a Schlenk equilibrium with BeCl2. DFT calculations suggest that in the absence of a coordinated base, both σ‐ and π‐bound forms would be potential energy minima.

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Beryllium Dichloride: Efficient promoter for the Addition of Organolithiums and Organomagnesiums to Cyclohexen-2-one

Cited by 10 publications

References 14 publications

Hybrid Porous Materials with High Surface Area Derived from Bromophenylethenyl‐Functionalized Cubic Siloxane‐Based Building Units

Hybrid Porous Materials with High Surface Area Derived from Bromophenylethenyl‐Functionalized Cubic Siloxane‐Based Building Units

1-Bromo-1-lithioethene: A Practical Reagent in Organic Synthesis

Bis(1,3‐trimethylsilylallyl)beryllium

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