14629-67-5Relevant academic research and scientific papers
5-Methylisoxazole-3-carboxamide-Directed Palladium-Catalyzed γ-C(sp3)-H Acetoxylation and Application to the Synthesis of γ-Mercapto Amino Acids for Native Chemical Ligation
Pasunooti, Kalyan Kumar,Yang, Renliang,Banerjee, Biplab,Yap, Terence,Liu, Chuan-Fa
, p. 2696 - 2699 (2016)
Palladium-catalyzed acetoxylation of the primary γ-C(sp3)-H bonds in the amino acids Val, Thr, and Ile was achieved using a newly discovered 5-methylisoxazole-3-carboxamide directing group. The γ-acetoxylated α-amino acid derivatives could be e
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.
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
Properties and reactions of substituted 1,2-thiazetidine 1,1-dioxides: Reactions of 3-acetoxy-β-sultams with sulfur nucleophiles
Merkle,Otto
, p. 657 - 660 (2007/10/02)
The acetate moiety of 3-acetoxy-β-sultams 2 is easily displaced by sulfur nucleophiles yielding the alkylthio-β-sultams 3 which are transformed into stable derivatives 4 by silylation. The synthesis of the cephem analogue 7 is described. Reactions of 2 wi
A versatile synthesis of functionalized thiols
Kraus,Andersh
, p. 2189 - 2192 (2007/10/02)
The reaction of trimer 6 and an alkyl lithium afforded thiolate 7 which reacted with primary halides to produce silyl thioethers in good to excellent yields. The silyl thioethers could be hydrolyzed to the thiols using HF in acetonitrile.
Silylation of Relatively Acidic Compounds with Alkyl Trimethylsilylacetates
Nakamura, Eiichi,Hashimoto, Koichi,Kuwajima, Isao
, p. 805 - 808 (2007/10/02)
Silylation of ketones, alcohols, alkanetiols, phenols, and carboxylic acids with alkyl trimethylsilylacetates has been described from synthetic and mechanistic points of view.
