5075-52-5Relevant articles and documents
Ring size effects in cyclic fluorophosphites: Ligands that span the bonding space between phosphites and PF3
Miles-Hobbs, Alexandra M.,Hunt, Eliza,Pringle, Paul. G.,Sparkes, Hazel A.
, p. 9712 - 9724 (2019/07/10)
The 5- to 8-membered cyclic fluorophosphites L5-8 have been prepared from the corresponding chlorophosphites which are derived from dihydroxyarenes or bis(trimethylsiloxy)arenes. Ligand L5 is very sensitive to hydrolysis but L6-8 are much more kinetically robust. The coordination chemistry of L5-8 has been explored with Mo(0), Pt(0) and Rh(i) and it is shown that the π-acceptor properties of L5-8 increase with decreasing ring size. The IR spectra and X-ray crystal structures of the [Mo(CO)4L2] complexes show that L5-8 lie between PF3 and P(OAr)3 in terms of their σ/π-bonding properties. The [PtL4] complexes are readily prepared from [Pt(nbe)3] and 4 equiv. of L5-8 whereas equilibrium mixtures of PtLx(nbe)y species form when 2 equiv. of L5-8 are added to [Pt(nbe)3]. The CO substitution reactions of [Rh2Cl2(CO)4] with L5-8 to give [Rh2Cl2L4] are evidence of the PF3-like ligand properties of L5-8. The trends in the properties of L5-8 are analysed in terms of their proximity to PF3 or P(OPh)3.
Multidimensional SuFEx Click Chemistry: Sequential Sulfur(VI) Fluoride Exchange Connections of Diverse Modules Launched From An SOF4 Hub
Li, Suhua,Wu, Peng,Moses, John E.,Sharpless, K. Barry
supporting information, p. 2903 - 2908 (2017/03/13)
Sulfur(VI) fluoride exchange (SuFEx) is a new family of click chemistry based transformations that enable the synthesis of covalently linked modules via SVI hubs. Here we report thionyl tetrafluoride (SOF4) as the first multidimensional SuFEx connector. SOF4 sits between the commercially mass-produced gases SF6 and SO2F2, and like them, is readily synthesized on scale. Under SuFEx catalysis conditions, SOF4 reliably seeks out primary amino groups [R-NH2] and becomes permanently anchored via a tetrahedral iminosulfur(VI) link: R?N=(O=)S(F)2. The pendant, prochiral difluoride groups R?N=(O=)SF2, in turn, offer two further SuFExable handles, which can be sequentially exchanged to create 3-dimensional covalent departure vectors from the tetrahedral sulfur(VI) hub.
Pinacolatoboron fluoride (pinBF) is an efficient fluoride transfer agent for diastereoselective synthesis of benzylic fluorides
Cresswell, Alexander J.,Davies, Stephen G.,Figuccia, Aude L.A.,Fletcher, Ai M.,Heijnen, Dorus,Lee, James A.,Morris, Melloney J.,Kennett, Alice M.R.,Roberts, Paul M.,Thomson, James E.
supporting information, p. 3373 - 3377 (2015/06/02)
The incorporation of alkoxy ligands within a range of alkoxyfluoroboranes and dialkoxyfluoroboranes results in fluoroborane reagents with attenuated Lewis acidity and increased ability to donate fluoride ion(s) when compared to boron trifluoride itself. Pinacolatoboron fluoride (pinBF), prepared in situ from BF3·OEt2 and bis(O-trimethylsilyl)pinacol, has been identified as an efficient fluoride donor which allows highly stereoselective SN1-type epoxide ring-opening (with retention of configuration) of a range of trans-β-methyl-substituted aryl epoxides to give the corresponding syn-fluorohydrins. The substrate scope of this transformation is more broad than the analogous protocol using boron trifluoride alone.
Preparation, characterization and use of 1,3-disulfonic acid imidazolium hydrogen sulfate as an efficient, halogen-free and reusable ionic liquid catalyst for the trimethylsilyl protection of hydroxyl groups and deprotection of the obtained trimethylsilanes
Shirini, Farhad,Khaligh, Nader Ghaffari,Akbari-Dadamahaleh, Somayeh
, p. 15 - 23 (2013/01/14)
Novel 1,3-disulfonic acid imidazolium hydrogen sulfate, a halogen-free ionic liquid, is a recyclable and eco-benign catalyst for the trimethylsilyl protection of hydroxyl groups at room temperature under solvent free conditions to afford trimethylsilanes in excellent yields (92-100%) and in very short reaction times (1-5 min). Deprotection of the resulting trimethylsilanes can also be achieved using the same catalyst in methanol. The catalyst was characterized by IR, 1H NMR, 13C NMR and MS studies. All the products were extensively characterized by IR, 1H NMR, MS, and elemental and melting point analyses. This new method consistently has the advantages of excellent yields and short reaction times. Further, the catalyst can be recovered and reused for several times without loss of activity. The work-up of the reaction consists of a simple separation, followed by concentration of the crude product and purification.
Poly(4-vinylpyridine) catalyzed chemoselective O-TMS protection of alcohols and phenols and N-Boc protection of amines
Shirini, Farhad,Khaligh, Nader Ghaffari
, p. 495 - 502 (2013/02/22)
Poly(4-vinylpyridine) (PVP) acts as an efficient and reusable catalyst for the selective and efficient trimethylsilylation of alcohols and phenols with hexamethyldisilazane (HMDS) and N-tert-butoxycarbonylation of amines with (Boc)2O. All reactions were performed under mild conditions in good to high yields. Iranian Chemical Society 2012.
Highly efficient and chemoselective trimethylsilylation of alcohols and phenols with hexamethyldisilazane (HMDS) catalyzed by reusable electron-deficient [TiIV(salophen)(OTf)2]
Yadegari, Maryam,Moghadam, Majid,Tangestaninejad, Shahram,Mirkhani, Valiollah,Mohammadpoor-Baltork, Iraj
experimental part, p. 332 - 338 (2012/03/12)
In the present work, highly efficient trimethylsilylation of alcohols and phenols with hexamethyldisilazane (HMDS) catalyzed by high-valent [Ti IV(salophen)(OTf)2] is reported. Under these conditions, primary, secondary and tertiary alcohols as well as phenols were silylated in short reaction times and high yields. It is noteworthy that this method can be used for chemoselective silylation of primary alcohols in the presence of secondary and tertiary alcohols and phenols. The catalyst was reused several times without loss of its catalytic activity.
Highly efficient and selective trimethylsilylation of alcohols and phenols with hexamethyldisilazane catalyzed by polystyrene-bound tin(IV) porphyrin
Gharaati, Shadab,Moghadam, Majid,Tangestaninejad, Shahram,Mirkhani, Valiollah,Mohammadpoor-Baltork, Iraj
experimental part, p. 87 - 95 (2012/05/05)
In the present work, investigation of the catalytic activity of tetrakis(p-aminophenyl)porphyrinatotin(IV) trifluoromethanesulfonate, [Sn IV(TNH2PP)(OTf)2], supported on chloromethylated polystyrene in the trimethylsilylation of alcohols and phenols with hexamethyldisilazane is reported. The prepared catalyst was characterized by elemental analysis, FT-IR and diffuses reflectance UV-Vis spectroscopic methods. This catalyst was used for selective trimethylsilylation of different alcohols and phenols with HMDS, with short reaction times and high yields. Also the catalyst is of high reusability and stability, in that it was recovered several times without loss of its initial activity.
Partition coefficients of ketones, phenols, aliphatic and aromatic acids, and esters in n-hexane/nitromethane
Kotowska, Urszula,Isidorov, Valery A.
scheme or table, p. 813 - 824 (2012/03/27)
Liquid-liquid partition is used in sample preparation and in countercurrent and liquid-liquid chromatographic separations. Partition coefficients are widely used in toxicology, environmental, and analytical chemistry. The K hn determination procedure for the n-hexane/ nitromethane system was optimized and partition coefficients for 99 ketones, esters and trimethylsilyl derivatives of phenols, aliphatic and aromatic acids were determined. For 130 compounds, Khn values were predicted using mathematical relationships between Khn and other physicochemical and structural parameters. Versita Sp. z o.o.
Preparation, characterization and use of 3-methyl-1-sulfonic acid imidazolium hydrogen sulfate as an eco-benign, efficient and reusable ionic liquid catalyst for the chemoselective trimethylsilyl protection of hydroxyl groups
Khaligh, Nader Ghaffari
experimental part, p. 63 - 70 (2011/12/02)
New and novel ionic liquid (3-methyl-1-sulfonic acid imidazolium hydrogen sulfate) is a recyclable and eco-benign catalyst for the chemoselective trimethylsilyl protection of hydroxyl groups under solvent-free conditions to afford trimethylsilanes in excellent yields (92-100%) and in very short reaction times (1-8 min). The catalyst was characterized by FT-IR, 1H NMR and 13C NMR studies. All the products were extensively characterized by 1H NMR, IR, GC-MS and melting point analyses. A mechanism for the catalytic activity is proposed. The catalyst can be recovered and reused without loss of activity. The work-up of the reaction consists of a simple separation, followed by concentration of the crude product and purification.
Succinimide-N-sulfonic acid: A mild, efficient, and reusable catalyst for the chemoselective trimethylsilylation of alcohols and phenols
Shirini,Khaligh, Nader Ghaffari
experimental part, p. 2156 - 2165 (2012/04/10)
Succinimide-N-sulfonic acid (SuSA) is easily prepared by the reaction of succinimide with chlorosulfonic acid. This reagent is able to efficiently catalyze the chemoselective trimethylsilylation of alcohols and phenols with hexamethyldisilazane (HMDS). All reactions were performed under mild reaction conditions, giving excellent yields. Copyright Taylor & Francis Group, LLC.
