18666-87-0Relevant articles and documents
The 2-(triphenylsilyl)ethoxycarbonyl-("Tpseoc"-) group: A new silicon-based, fluoride cleavable oxycarbonyl protecting group highly orthogonal to the Boc-, Fmoc- and Cbz-groups
Golkowski, Martin,Ziegler, Thomas
experimental part, p. 4695 - 4718 (2011/08/10)
Starting from 2-(triphenylsilyl)ethanol a new oxycarbonyl protecting group cleavable by fluoride ion induced Peterson-elimination has been developed. Known 2-(triphenylsilyl)ethanol has been prepared from commercially available triphenylvinylsilane by a hydroboration-oxidation sequence using the sterically hindered borane reagent 9-BBN. The silyl alcohol was subsequently transformed into its chloroformate, imidazolylcarboxylic acid ester and p-nitrophenyl carbonate and used in standard protocols for the formation of carbamates and carbonates. The Tpseoc group proved to be highly resistant against acidic conditions applied in removal of tert-butyl esters and the t-Boc-group. It also withstood catalytic hydrogenation, treatment with morpholine, methylhydrazine and Pd-reagents/allyl-scavanger combinations, conditions required to cleave Cbz-, Fmoc-, phthalimide- and Alloc-groups. The Tpseoc-group is cleaved upon treatment with TBAF/CsF at 0 °C or r.t. with cleavage times reaching from 10 min. to 24 h. Its orthogonality, ease of cleavage and UV-detectability makes the Tpseoc-group a promising alternative to other widely used silicon based amine protecting groups like the Teoc- and SES-groups.
Silyl phosphorylating reagents and methods of using them
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, (2008/06/13)
Oligonucleotide phosphorylating reagents wherein the silyl moiety has three bulky substituents, such as phenyl or t-butyl, and the silyl moiety is attached to the carbon of an ethanol group whose hydroxyl is an activated phosphate group. The preferred com
Substituted silyl alcohols
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, (2008/06/13)
Novel silyl alcohols having bulky substituents bonded to the silicon, and the silyl group attached to a carbon include the preferred 2-silyl-ethan-1-ols. A method for synthesizing substituted alcohols include hydrosilation of a vinylic ester, especially v
Process for synthesis of silyl alcohols
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, (2008/06/13)
Novel silyl alcohols having bulky substituents bonded to the silicon, and the silyl group attached to a carbon include the preferred 2-silyl-ethan-1-ols. A method for synthesizing silyl substituted alcohols include hydrosilation of a vinylic ester, especi
A regiodefined synthesis of α-trimethylsilyl ketones catalyzed by rhodium(I) hydride complex
Sato, Susumu,Matsuda, Isamu,Izumi, Yusuke
, p. 71 - 88 (2007/10/02)
Regiodefined synthesis of α-trimethylsilyl ketones is attained by one of three different routes: isomerization of β-trimethylsilyl allyl alcohols (route A), isomerization of β'-trimethylsilyl allyl alcohols (route B), and dehydrogenation of β-trimethylsil
Organosilicon compounds with functional groups proximate to silicon. XVII. Synthetic and mechanistic aspects of the lithiation of α,β-epoxyalkylsilanes and related α-heterosubstituted epoxides
Eisch, John J.,Galle, James E.
, p. 293 - 314 (2007/10/02)
A series of α-heterosubstituted epoxides, , has been found to undergo lithiation in the temperature range of -75 to -115 deg C at the C-H bond of the epoxide.The substituent Z could be Me3Si, Ph3Si, n-Bu3Sn, Ph3Sn, PhSO2, (OEt)2PO and Ph; the groups R and R' were H, Ph and n-C6H13; and the lithiating reagents were n-butyllithium, t-butyllithium and lithium diisopropylamide in donor media of THF or TMEDA.The lithiation occurs with retention of configuration and the resulting lithio-epoxide is unstable above 0 deg C, decomposing in a carbenoid manner.The lithiation is facile except for compounds where Z and R (an alkyl or aryl) are cis-oriented; where Z = R3Sn, lithiation occurs by tin-lithium, rather than hydrogen-lithium, exchange.The lithio-epoxides thereby generated can be quenched with various reagents to yield epoxides where the epoxide H has been replaced by D, Me3Sn, R, RCO and COOH.The utility of this procedure in organic synthesis is emphasized.Finally, the possible explanations for the acidity of such α-heterosubstituted epoxides and for the relative stability of the derived lithio-epoxides are considered and assessed.
