Synthetic methods and reactions. 62. Transformations with chlorotrimethylsilane/sodium iodide, a convenient in situ iodotrimethylsilane reagent

Oláh, George A.; Narang, Subhash C.; Gupta, B. G. Balaram; Malhotra, Ripudaman

doi:10.1021/jo01322a012

Cited by 493 publications

(174 citation statements)

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“…The adduct undergoes CID at 25 eV (lab) by loss of fluorotrimethylsilane (ϳ20%), loss of methanol (ϳ70%) and loss of methane (ϳ10%). Surprisingly, loss of methanol was the major pathway, unlike all of the other RSi(CH 3 ) 3 F Ϫ systems that gave predominantly loss of FSi(CH 3 ) 3 . Although it is in principle possible to model a system with three channels, because of the dissimilarity between the dissociation of this ion and the other alkoxysiliconates, it was not examined further.…”

Section: Reaction Of F ϫ With Methoxytrimethylsilane Ch 3 Osi(ch 3 )mentioning

confidence: 77%

“…In the higherpressure conditions of the flowing afterglow, the adduct (CH 3 ) 3 SiOSi(CH 3 ) 3 F Ϫ (m/z 181) is also formed. Upon CID, the adduct loses fluorotrimethylsilane leaving trimethylsiloxide, (CH 3 ) 3 SiO Ϫ (m/z 89) as the major product. A very small amount of HF loss is also observed, giving (CH 3 ) 3 SiOSi(CH 3 ) 2 CH 2 Ϫ (m/z 161).…”

Section: Reaction Of F ϫ With Hexamethyldisiloxane (Ch 3 ) 3 Siosi(cmentioning

confidence: 99%

“…A very small amount of HF loss is also observed, giving (CH 3 ) 3 SiOSi(CH 3 ) 2 CH 2 Ϫ (m/z 161). Cross sections for formation of (CH 3 ) 3 SiO Ϫ are shown in Figure 1. The bond dissociation energy of trimethylsiloxide to fluorotrimethylsilane was found to be 0.93 Ϯ 0.09 eV (21.4 Ϯ 2.1 kcal/mol, Figure 1, Table 1).…”

Section: Reaction Of F ϫ With Hexamethyldisiloxane (Ch 3 ) 3 Siosi(cmentioning

confidence: 99%

“…Indeed, silyl moieties are often used as protecting groups because of the ease of their removal with fluoride and chloride [2,3]. Extension of this Group 14 chemistry has led to the process of fluoride-induced destannylation, also wellknown within the literature [4,5].…”

mentioning

confidence: 99%

“…In this work, pentavalent siliconates are prepared by the termolecular addition of fluoride to the silane, giving an adduct RSi(CH 3 ) 3 3 , the 2,2,2-trifluoroethoxy substituent is expected to have a smaller binding affinity because of the electron-withdrawing effect of the trifluoromethyl group. Although isoproproxy-and 2,2,2-trifluoroethoxytrimethylsilane have limited synthetic use, ethoxytrimethylsilane is an important polysiloxane precursor and is used to prepare esters, ethers and glycols [51,52].…”

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confidence: 99%

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Fluorotrimethylsilane affinities of anionic nucleophiles: A study of fluoride-induced desilylation

Krouse

Wenthold

2005

J. Am. Soc. Mass Spectrom.

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In this study, preparation and decomposition of five novel pentavalent fluorosiliconates, RSi(CH 3 ) 3 F Ϫ (R ϭ CH 3 CH 2 O, CF 3 CH 2 O, (CH 3 ) 2 CHO, (CH 3 ) 3 SiO, and (CH 3 ) 3 SiNH) is used to investigate the process of fluoride-induced desilylation. The siliconates were characterized by collision-induced dissociation and energy-resolved mass spectrometry. Decomposition of RSi(CH 3 ) 3 F Ϫ leads to loss of the nucleophile R Ϫ and FSi(CH 3 ) 3 , except in the case of (CH 3 ) 3 SiNHSi(CH 3 ) 3 F Ϫ , where HF loss is also observed. Ion affinities for FSi(CH 3 ) 3 have been measured for all five nucleophiles, and compare well with computational predictions. The observed trend of the bond dissociation energies resembles the trend of ⌬H acid values for the corresponding conjugate acids, RH. Additionally, this data has been incorporated with existing thermochemistry to derive fluoride affinities for four of the silanes (R ϭ CH 3 CH 2 O, (CH 3 ) 2 CHO, (CH 3 ) 3 SiO, and (CH 3 ) 3 SiNH). We use the fluoride affinity of the silanes and the FSi(CH 3 ) 3 affinity of the departing nucleophilic anion to assess the feasibility of fluorideinduced desilylation of the silanes examined in this work. (J Am Soc Mass Spectrom 2005, 16, 697-707)

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Section: Reaction Of F ϫ With Methoxytrimethylsilane Ch 3 Osi(ch 3 )mentioning

confidence: 77%

Section: Reaction Of F ϫ With Hexamethyldisiloxane (Ch 3 ) 3 Siosi(cmentioning

confidence: 99%

Section: Reaction Of F ϫ With Hexamethyldisiloxane (Ch 3 ) 3 Siosi(cmentioning

confidence: 99%

mentioning

confidence: 99%

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confidence: 99%

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Fluorotrimethylsilane affinities of anionic nucleophiles: A study of fluoride-induced desilylation

Krouse

Wenthold

2005

J. Am. Soc. Mass Spectrom.

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Synthesis of saturated fatty acids 11C(13C)-labelled in the ω-methyl position

Neu

Kihlberg

Långström

1997

J Label Compd Radiopharm

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A method for the preparation of saturated fatty acids 11C (13C)‐labelled in the ω‐methyl position is described. A highly reactive zerovalent copper complex was prepared from lithium naphtalenide reduced lithium(2‐thienyl)iodocuprate. The labelling precursors were obtained by addition of tert‐butyl ω‐iodocarboxylates to the organocuprate and these were reacted with [11C]methyl iodide to form 11C‐labelled, protected intermediates. The tert‐butyl ester protecting group was rapidly removed with trifluoroacetic acid, affording fatty acids 11C‐labelled in the ω‐methyl position. A solid phase extraction method was developed and preceded final HPLC purification. In a typical run starting with 2.75 GBq of [11C]methyl iodide, 375 MBq (66%) [16‐11C]palmitic acid was obtained within 46 min from the end of the radionuclide production. © 1997 John Wiley & Sons, Ltd.

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Chlorotrimethylsilane

Leahy

2001

Encyclopedia of Reagents for Organic Synthesis

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Synthetic methods and reactions. 62. Transformations with chlorotrimethylsilane/sodium iodide, a convenient in situ iodotrimethylsilane reagent

Cited by 493 publications

References 0 publications

Fluorotrimethylsilane affinities of anionic nucleophiles: A study of fluoride-induced desilylation

Fluorotrimethylsilane affinities of anionic nucleophiles: A study of fluoride-induced desilylation

Synthesis of saturated fatty acids 11C(13C)-labelled in the ω-methyl position

Chlorotrimethylsilane

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