Co-ordination at a silicon atom: effects on optical rotatory dispersion of α-silyl-ketones

Corriu, Robert J. P.; Masse, J.

doi:10.1039/c29690000589

Cited by 10 publications

(9 citation statements)

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“…Since the pioneering work of Sommer from 1959 to the middle of the 1960s, stereochemistry on a chiral silicon center in organic silicon compounds has received much attention . Optically active silicon compounds have been obtained by optical resolution, kinetic resolution, or asymmetric synthesis . Sommer's optical resolution method 1 using the (−)-menthoxy group involves separation of (±)-(1-naphthyl)phenylmethyl[(−)- menthoxy]silane by fractional crystallization.…”

Section: Introductionmentioning

confidence: 99%

“…Alternatively, Holt et al developed a mild reaction of (1-naphthyl)phenylmethylsilane with (−)-menthol in the presence of Pd−C at room temperature . The (−)-menthoxy group has also been used to resolve difunctional silanes, 3a-e organosilicon compounds containing Si−Si and Si−Ge linkages, 3f,g and cyclic organosilicon compounds. 3h-j Optical resolution of α-amino organosilanes by use of (+)-tartaric acid has also been reported 3k. Kinetic resolution has been achieved by partial reduction of racemic methoxysilanes 4a,b with chiral complexes of lithium aluminum hydride and by alcoholysis of (1-naphthyl)phenylchlorosilane with (−)-menthol 3b.…”

Section: Introductionmentioning

confidence: 99%

“…The (−)-menthoxy group has also been used to resolve difunctional silanes, 3a-e organosilicon compounds containing Si−Si and Si−Ge linkages, 3f,g and cyclic organosilicon compounds. 3h-j Optical resolution of α-amino organosilanes by use of (+)-tartaric acid has also been reported 3k. Kinetic resolution has been achieved by partial reduction of racemic methoxysilanes 4a,b with chiral complexes of lithium aluminum hydride and by alcoholysis of (1-naphthyl)phenylchlorosilane with (−)-menthol 3b. Asymmetric synthesis has also been a way to optically active silicon compounds, which includes the reaction of prochiral bis(acetamido)silanes with optically active amino acids, 5b,c alcoholysis of prochiral dihydrosilanes by use of an optically active alcohol and/or chiral catalyst, 5d,e catalytic asymmetric hydrosilation of carbonyl compounds with prochiral dihydrosilanes, 5f-j and reaction of dialkoxysilanes containing chiral alkoxy groups with organometals. 5k,l …”

Section: Introductionmentioning

confidence: 99%

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Optical Resolution and Epimerization of Fluorosilane Having an Optically Active Amino Group: A New, Convenient Access to Optically Active Silicon Compounds

et al. 1999

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The diastereomeric (amino)fluorosilane 2 is prepared from the prochiral (1-naphthyl)phenyldifluorosilane 5 with optically active bis[(R)-1-phenylethyl]amine (3). The two isomers of 2 can be easily separated due to their large solubility difference in CH3NO2. In addition, 2 undergoes epimerization at the silicon atom in the presence of a catalytic amount of AgF. Stereospecific methylation and the deamination−fluorination of 2 give the enantiomerically pure (1-naphthyl)phenylmethylfluorosilane (1).

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Optical Resolution and Epimerization of Fluorosilane Having an Optically Active Amino Group: A New, Convenient Access to Optically Active Silicon Compounds

et al. 1999

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“…Eventually, Sommer et al (13) also provided evidence against the S^l-Si mechanism by showing that replacing the phenyl on _2 with perfluorophenyl produced an increase in the rate of racemization which is consistent with the work of Corriu et al (10) and their explanation of the reaction but not with an S^^-Si mechanism.…”

Section: Introductionmentioning

confidence: 64%

“…Corriu et al [10] discovered that the solvent-induced racemization reported by Sommer et al (7) was second order with respect to the racemizing solvents and that the key factor in racemization was the nucleophilic power of the solvent and not the dielectric constant. The best racemizing solvents were HMPA, DMF, and DMSO, but relatively low polarity solvents such as ethers and esters were also generally able to cause racemization.…”

Section: Introductionmentioning

confidence: 99%

Sterically hindered silyl perchlorates: synthetic and mechanistic studies

Tully

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Sterically hindered silyl perchlorates were initially examined in hopes of finding evidence of a trivalent cationic silicon species or silylenium ion. Although our studies failed to uncover solid evidence of ionization, it was dis covered that these compounds had unique synthetic potential as silylating agents. All silyl perchlorates examined to date have been found to be highly reactive, relative to their halogenide counterparts, toward nucleophilic agents. t^Butyldimethylsilyl perchlorate offers a significant improvement over the widely used t-butyldimethylsilyl chloride in that it reacts readily with tertiary alcohols. The di-tbutylmethylsilyl moity, a heretofore unknown alcohol blocking group, was also examined and found to be dramatically more resistant to acidic and basic solvolysis than the t^butyldimethylsilyl group. The route to prepare the tri-t^butylsilylperchlorate, although successful, was found to be too arduous for the group to be of any synthetic utility in the pro tection of alcohols. Silyl perchlorates were found to react readily with carbanions. Di-t-butylfluorenyl silane prepared in this manner was used as a precursor to a sterically and electronically stabilized silene; however, attempts to effect the conversion failed. The reaction of silyl perchlorates with carbanions is of limited utility in the synthesis of sterically hindered organosilanes since it was found that reaction of di-^-butylsilyl perchlorate with a carbanion containing hydrogens beta to the anionic center, such as ^t-butyllithium resulted in reduction of the perchlorate group rather than alkylation at silicon. All silyl perchlorates examined, save the tri-^-butyl, were found to be readily available through a hydride exchange reaction between the silyl hydride and trityl per chlorate. The kinetics of this and other similar hydride exchange reactions involving trityl fluoroborate and hexafluoro antimonate were examined and the reaction was found to be second order overall, first order in silane and first order in trityl cation. The reaction was demonstrated to be anion independent with these ionic trityl salts, thus suggesting that the reaction may proceed through a silylenium ion. Rather anomalous results were obtained with trityl bromide suggesting that perhaps a free radical chain reaction mechanism may be involved.

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