Iodine-mediated rearrangements of diallylsilanes

O’Neil, Gregory W.; Cummins, Elizabeth J.

doi:10.1016/j.tetlet.2017.07.045

Cited by 8 publications

(4 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As part of an ongoing program investigating new reactions of allylsilanes, − we observed that epoxysilanes, prepared by epoxidation of the corresponding allylsilane, are cleanly converted to the corresponding fluorohydrin upon treatment with triethylamine trihydrofluoride (HF·Et 3 N; Table ). Other HF sources such as Olah’s reagent (HF·Py) resulted in significant decomposition.…”

Section: Resultsmentioning

confidence: 99%

Regioselective Fluorohydrin Synthesis from Allylsilanes and Evidence for a Silicon–Fluorine Gauche Effect

Clover,

Jones,

Berger

et al. 2024

J. Org. Chem.

View full text Add to dashboard Cite

Allylsilanes can be regioselectively transformed into the corresponding 3-silylfluorohydrin in good yield using a sequence of epoxidation followed by treatment with HF•Et 3 N with or without isolation of the intermediate epoxide. Various siliconsubstitutions are tolerated, resulting in a range of 2-fluoro-3-silylpropan-1-ol products from this method. Whereas other fluorohydrin syntheses by epoxide opening using HF•Et 3 N generally require more forcing conditions (e.g., higher reaction temperature), opening of allylsilane-derived epoxides with this reagent occurs at room temperature. We attribute this rate acceleration along with the observed regioselectivity to a β-silyl effect that stabilizes a proposed cationic intermediate. The use of enantioenriched epoxides indicates that both S N 1-and S N 2-type mechanisms may be operable depending on substitution at silicon. Conformational analysis by NMR and theory along with a crystal structure obtained by X-ray diffraction points to a preference for silicon and fluorine to be proximal to one another in the products, perhaps favored due to electrostatic interactions.

show abstract

Section: Resultsmentioning

confidence: 99%

Regioselective Fluorohydrin Synthesis from Allylsilanes and Evidence for a Silicon–Fluorine Gauche Effect

Clover,

Jones,

Berger

et al. 2024

J. Org. Chem.

View full text Add to dashboard Cite

show abstract

“…1-Allyl-1-cyclohexyloxysiletane (1). 4 To a Schlenk flask containing diallylsiletane (1.1 g, 6.9 mmol, 1.0 equiv) in DCM (35 mL) was added I 2 (180 mg, 10 mol %) at room temperature, and the resulting red solution was stirred for 10 min. Cyclohexanol (0.72 mL, 6.9 mmol, 1.0 equiv) was then added, and the solution was heated to 35 °C for 30 min.…”

Section: ■ Conclusionmentioning

confidence: 99%

“…3 Our group recently described a novel synthesis of this compound by iodine-catalyzed monoetherification of diallylsilacyclobutane (Scheme 1). 4 With reliable access to useful quantities of 1, we now wish to report on its use in a series of carbonyl allylsilylations. In particular, we found that reagents of type 1 are capable of remarkably chemoselective nucleophilic additions to various hydroxylsubstituted carbonyls.…”

mentioning

confidence: 99%

Chemoselective Carbonyl Allylations with Alkoxyallylsiletanes

et al. 2019

Self Cite

View full text Add to dashboard Cite

Alkoxyallylsiletanes are capable of highly chemo-and diastereoselective carbonyl allylsilylations. Reactive substrates include salicylaldehydes and glyoxylic acids. Chemoselectivity in these reactions is thought to arise from a mechanism involving first exchange of the alkyoxy group on silicon with a substrate hydroxyl followed by activation of a nearby carbonyl by the Lewis acidic siletane and intramolecular allylation. In this way, substrates containing multiple reactive carbonyl groups (e.g. dialdehyde or triketone) can be selectively monoallylated, even overcoming inherent electrophilicity bias (e.g. nucleophilic addition to a ketone in the presence of an aldehyde).

show abstract

“…As part of an ongoing program investigating new reactions of allylsilanes, [11][12][13] we observed that epoxysilanes, prepared by epoxidation of the corresponding allylsilane, are cleanly converted to the corresponding fluorohydrin upon treatment with triethylamine trihydrofluoride (HF•Et3N; Table 1). Other HF sources such as Olah's reagent (HF•pyridine) resulted in significant decomposition.…”

mentioning

confidence: 99%

Regioselective Fluorohydrin Synthesis from Allylsilanes

Clover

Jones

O’Neil

2023

Preprint

View full text Add to dashboard Cite

Allysilanes can be regioselectively transformed into the corresponding 3-silylfluorohydrin in good yield using a sequence of epoxidation followed by treatment with HF-Et3N with or without isolation of the intermediate epoxide. Various silicon-substitution is tolerated, resulting in a range of 2-fluoro-3-silylpropan-1ol products from this method. Whereas other fluorohydrin syntheses by epoxide opening using HF-Et3N generally require more forcing conditions (e.g. higher reaction temperature), opening of allylsilane-derived epoxides with this reagent occurs at room temperature. We attribute this rate acceleration along with the observed regioselectivity to a beta-silyl effect that stabilizes a proposed cationic intermediate. The use of enantioenriched epoxides produces similarly enantioenriched fluorohydrins suggestive of an SN2-type mechanism.

show abstract

Iodine-mediated rearrangements of diallylsilanes

Cited by 8 publications

References 24 publications

Regioselective Fluorohydrin Synthesis from Allylsilanes and Evidence for a Silicon–Fluorine Gauche Effect

Regioselective Fluorohydrin Synthesis from Allylsilanes and Evidence for a Silicon–Fluorine Gauche Effect

Chemoselective Carbonyl Allylations with Alkoxyallylsiletanes

Regioselective Fluorohydrin Synthesis from Allylsilanes

Contact Info

Product

Resources

About