38325-59-6Relevant academic research and scientific papers
Tandem Insertion/[3,3]-Sigmatropic Rearrangement Involving the Formation of Silyl Ketene Acetals by Insertion of Rhodium Carbenes into S-Si Bonds
Combs, Jason R.,Lai, Yin-Chu,Van Vranken, David L.
supporting information, p. 2841 - 2845 (2021/05/05)
Allyl 2-diazo-2-phenylacetates are shown to react with trimethylsilyl thioethers in the presence of rhodium(II) catalysts to generate α-allyl-α-thio silyl esters. The transformation involves a tandem process involving formal rhodium-catalyzed insertion of the carbene group into the S-Si bond to generate a silyl ketene acetal, followed by a spontaneous Ireland-Claisen rearrangement. The silyl ester products were isolated as the corresponding carboxylic acids after aqueous workup. Intramolecular cyclopropanation of the allyl fragment generally competes with addition of the heteroatom to the carbene center. The reaction occurs under mild conditions and in high yield, allowing for rapid entry into rearrangement tetrasubstituted products. Propargyl esters were shown to generate the corresponding α-allenyl products.
P4VPy–CuO nanoparticles as a novel and reusable catalyst: application at the protection of alcohols, phenols and amines
Shirini, Farhad,Fallah-Shojaei, Abdollah,Abedini, Masoumeh,Samavi, Laleh
, p. 1699 - 1712 (2016/07/27)
P4VPy–CuO nanoparticles were synthesized using ultrasound irradiations. Relevant properties of the synthesized nanoparticles were investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Fourier transform infrared spectroscopy. After identification, the prepared reagent was used for the promotion of different types of protection reactions of alcohols, phenols and amines. Easy workup, short reaction times, excellent yields, relatively low cost and reusability of the catalyst are the striking features of the reported methods.
Novel protocol for the synthesis of organic ammonium tribromides and investigation of 1,1′-(Ethane-1,2-diyl)dipiperidinium bis(tribromide) in the silylation of alcohols and thiols
Dey, Rupa R.,Paul, Bappi,Dhar, Siddhartha S.,Bhattacharjee, Sushmita
supporting information, p. 1545 - 1547 (2015/02/19)
A novel and efficient protocol for the synthesis of organic ammonium tribromides (OATBs) is developed by using inexpensive and eco-friendly periodic acid as an oxidant for the conversion of Br-to Br3-. The method does not use any mineral acid and metal oxidants. The protocol is utilized to synthesize a new bis(tribromide) viz., 1,1′-(ethane-1,2-diyl)dipiperidinium bis(tribromide) (EDPBT). EDPBT is investigated as a catalyst in the silylation of alcohols and thiols by HMDS (hexamethyldisilazane) under solvent-free conditions.
Synthesis and characterization of 2-carboxyethyltriphenyl phosphonium tribromide and its application as catalyst in silylation of alcohols and thiols under solvent-free condition
Dey, Rupa Rani,Dhar, Siddhartha Sankar
supporting information, p. 2355 - 2363 (2014/07/22)
A phosphonium-based catalyst, 2-carboxyethyltriphenyl phosphonium tribromide (CTPTB), has been synthesized by reacting triphenyl phosphine with acrylic acid and potassium bromide under solvent-free condition followed by oxidation of Br- to with KMnO4. This hitherto unknown tribromide reagent is characterized by ultraviolet-visible, Fourier transform-infrared, 1H NMR, and 31P NMR spectroscopy. Its efficacy as catalyst is established by investigating its catalytic activity in silylation of alcohols and thiols by hexamethyl disilazane (HMDS). It is found to be a very good catalyst and selectively and efficiently catalyzes the silylation reactions. Copyright
Diaryl ether synthesis in supercritical carbon dioxide in batch and continuous flow modes
Lee, Jin-Kyun,Fuchter, Matthew J.,Williamson, Rachel M.,Leeke, Gary A.,Bush, Edward J.,McConvey, Ian F.,Saubern, Simon,Ryan, John H.,Holmes, Andrew B.
supporting information; experimental part, p. 4780 - 4782 (2009/03/12)
A high yielding, batch mode synthesis of diaryl ethers and sulfides by an SNAr fluoride-mediated process in scCO2 has been developed; the use of a polymer-supported imidazolium fluoride reagent in batch mode led to the development of
Poly(N-bromobenzene-1,3-disulfonamide) and N,N,N′,N′-tetrabromobenzene-1,3-disulfonamide as novel catalytic reagents for silylation of alcohols, phenols, and thiols using hexamethyldisilazane
Ghorbani-Vaghei, Ramin,Zolfigol, Mohammad Ali,Chegeny, Mahdieh,Veisi, Hojat
, p. 4505 - 4508 (2007/10/03)
Poly(N-bromobenzene-1,3-disulfonamide) [PBBS] and N,N,N′,N′-tetrabromobenzene-1,3-disulfonamide [TBBDA] are effective catalysts for the silylation of alcohols, phenols, and thiols in the presence of hexamethyldisilazane with, or without solvent, and also under microwave irradiation.
Polysulfonylamines, XXXVI, Trimethylsilyl Dimesylamine: Preparation, NMR-Spectroscopic Characterization, and Reactivity as a Silylating Agent
Blaschette, Armand,Wieland, Elke,Hamann, Thomas,Harris, Robin K.
, p. 1693 - 1700 (2007/10/02)
(CH3)3SiN(SO2CH3)2 (1), m.p. 69-70 deg C, is obtained by metathesis of AgN(SO2CH3)2 with (CH3)3SiCl (improvement of a known procedure) or, more conveniently, by silylation of HN(SO2CH3)2 with 2NH.The (1)H, (13)C and (29)Si NMR solution spectra and the (29)Si NMR solid-state spectrum suggest the constitution of 1 in solution (CDCl3, CD2Cl2, CDCl2-CDCl2) to be an equilibrium mixture of the N-silylated form (CH3)3Si-N(SO2CH3)2 (I) and the O-silylated form (CH3)3Si-O-S(O)(CH3) = NSO2CH3 (II) in a molar ratio of 2:1 at room temperature, whereas in the known crystal structure of 1 only form I is present.The solid-state NMR experiment acted as a bridge between X-ray crystallography and solution-state NMR, enabling assignments of the resonances to be made with confidence to the tautomers.At room temperature, form II undergoes a rapid intramolecular 1.5-migration of silicon between oxygen centers of the two sulfonyl groups.As shown by kinetic measurements using (1)H NMR spectroscopy, 1 is a highly reactive agent for silylating ketones in the presence of triethylamine.Hydroxy and thiol functions, even when sterically hindered, are silylated by 1 in uncatalyzed reactions.It is further shown that HN(SO2CH3)2 is an efficient catalyst for silylations with 2NH. Key words: Polysulfonylamines, Trimethylsilyl Dimesylamine, N,O- and O,O-Silyl Migration, Silylation of Hydroxy and Thiol Functions, Solid State (29)Si NMR
Synthesis, Structure, and Catalytic Activity of μ-Alkylthio- and μ-Arylthio-μ-chloro-dicarbonylbis(tri-tert-butylphosphane)dirhodium Complexes
Schumann, Herbert,Cielusek, Guy,Jurgis, Stanislaw,Hahn, Ekkehardt,Pickardt, Joachim,et al.
, p. 2825 - 2838 (2007/10/02)
Tetracarbonyldi-μ-chloro-dirhodium (1) reacts with tri-tert-butylphosphane and alkyl or aryl trimethylsilyl sulfides 4 to give complexes tBu3)2Cl(SR)> (5a-i).The complexes 5h,i with the surface active trialkoxysilyl groups are fixed onto a fused silica support.The X-ray structural analyses of tBu3)2Cl(StBu)> (5c) and tBu3)2Cl(SC6H4Cl)> (5g) indicate a cis-configuration of the tri-tert-butylphosphane ligands.The new complexes catalyze the isomerization of 1-octen-3-ol (10) into 3-octanone (11), of 4-allylanisole (12) into cis- and trans-4-(1-propenyl)anisole (13), of trans-stilbene oxide (14) into desoxybenzoin (15), the transfer hydrogenation of α,β-unsaturated ketones by formic acid (16 -> 17), and the transfer hydrogenolysis of trihalomethyl compounds (18, 20) by halogen free alcohols.
