101-41-7Relevant articles and documents
Solvent-modulated chemoselective deprotections of trialkylsilyl esters and chemoselective esterifications
Lee, Adam Shih-Yuan,Su, Feng-Yih
, p. 6305 - 6309 (2005)
A series of trialkylsilyl esters were deprotected or transesterificated into their corresponding carboxylic acids or methyl esters under a catalytic amount of CBr4 in alcohol reaction system. This method enables to desilylate secondary sp3-carbon, sp2-carbon, sp-carbon and aryl tethered trialkylsilyl esters to carboxylic acids, whereas primary sp 3-carbon tethered trialkylsilyl esters were further converted into their methyl esters under CBr4/MeOH reaction conditions. The highly chemoselective deprotections can be modulated and achieved by the introduced protecting trialkylsilyl groups and the used alcohols such as MeOH and EtOH under this photochemically-induced reaction conditions.
Design and synthesis of sulfonated carbons with amphiphilic properties
Jia, Rong,Ren, Jiawen,Liu, Xiaohui,Lu, Guanzhong,Wang, Yanqin
, p. 11195 - 11201 (2014)
A new type of sulfonated carbon material with amphiphilic properties was synthesized by the hydrothermal carbonization of a mixture of furfural-sodium dodecylbenzene sulfonate at 180 °C in an autoclave. The addition of SDBS is necessary for the production of materials with long carbon chains and is possibly used to improve the solubilization of long carbon-chain and steric compounds such as pivalic acid. The resulting material was characterized by N2 adsorption, XPS, 13C NMR, XRD and FTIR. The synthesized material was proven to be a highly efficient solid-acid catalyst in reactions such as the esterification of pivalic acid with alcohols, and catalytic performance much better than that of conventional solid acid catalysts, e.g. Amberlyst-15 and Nafion resin, was observed.
Synthesis of Benzo[a]carbazoles and an Indolo[2,3-a]carbazole from 3-Aryltetramic Acids
Truax, Nathanyal J.,Banales Mejia, Fernando,Kwansare, Deborah O.,Lafferty, Megan M.,Kean, Maeve H.,Pelkey, Erin T.
, p. 6808 - 6815 (2016)
A simple and flexible approach to 3-pyrrolin-2-one fused carbazoles is disclosed. The key step involves the BF3-mediated electrophilic substitution of indoles with N-alkyl-substituted 3-aryltetramic acids, which provides access to indole-substituted 3-pyrrolin-2-ones. Scholl-type oxidative cyclizations of these materials led to the formation of the corresponding 3-pyrrolin-2-one-fused benzo[a]carbazoles and indolo[2,3-a]carbazoles. This work represents the first synthesis of the benzo[a]pyrrolo[3,4-c]carbazol-3(8H)-one ring system, while the indolo[2,3-a]pyrrolo[3,4-c]carbazol-5-one ring system is found in a number of biologically active compounds including the protein kinase C (PKC) inhibitor, staurosporine.
Secondary metabolites by chemical screening, 39: Acyl α-L- rhamnopyranosides, a novel family of secondary metabolites from streptomyces sp.: Isolation and biosynthesis
Grond, Stephanie,Langer, Hans-Jo?rg,Henne, Petra,Sattler, Isabel,Thiericke, Ralf,Grabley, Susanne,Za?hner, Hans,Zeeck, Axel
, p. 929 - 937 (2000)
In the course of our chemical screening program, the novel acyl α-L- rhamnopyranosides (1-6) were detected as metabolites from five different strains of Streptomycetes. The structures of all these compounds were elucidated by chemical and spectroscopic methods. The biosynthesis of 1 and 3 was established by feeding 13C-labelled acetate, glycerol, and d-glucose to Streptomyces griseoviridis (strain Tu 3634), and resulted in a complete labelling pattern of the 2,4-dimethyl-3-furanylcarbonyl and benzoyl residues, as well as the rhamnose moiety. These results reveal biosynthetic pathways of general importance and give an insight into the generation of the hexose phosphates, from which deoxysugars are formed. The acyl rhamnosides are members of a novel family of microbial metabolites and are considered as rhamnoconjugates from Streptomycetes.
Three-component coupling reaction of benzylic halides, carbon dioxide, and N,N-dimethylformamide by using paired electrolysis: Sacrificial anode-free efficient electrochemical carboxylation of benzylic halides
Senboku, Hisanori,Nagakura, Kotaro,Fukuhara, Tsuyoshi,Hara, Shoji
, p. 3850 - 3856 (2015)
Sacrificial anode-free efficient electrochemical carboxylation of benzylic halides was successfully performed by using a paired electrolysis protocol. Constant-current electrolysis of a DMF solution of benzylic halides in the presence of carbon dioxide using a one-compartment cell equipped with a Pt plate cathode and a Pt wire anode (quasi-divided cell) resulted in efficient three-component coupling reaction of benzylic halides, carbon dioxide and DMF to yield N-methyl-N-(phenylacetoxy)methylformamides, as carboxylated coupling products, in good yields.
Scandium triflate catalyzed transesterification of carboxylic esters
Remme, Nicole,Koschek, Katharina,Schneider, Christoph
, p. 491 - 493 (2007)
The direct transesterification of carboxylic esters is efficiently catalyzed with Sc(OTf)3 (10 mol%) in boiling alcoholic solvent. Methyl, ethyl, isopropyl, and allyl esters were prepared from a broad range of different substrates in high yields. The application of microwave irradiation led to significantly reduced reaction times. Georg Thieme Verlag Stuttgart.
Phenylsilane as an effective desulfinylation reagent
Midura, Wanda H.,Rzewnicka, Aneta,Krysiak, Jerzy A.
, p. 1513 - 1517 (2017)
The reduction using phenylsilane in a KOH-catalyzed system was applied successfully to the conversion of sulfinyl-substituted cyclopropylcarboxylates into the corresponding alcohols. The presence of sulfinyl substituents in the α-position to the carboxylate group caused a desulfinylation product formation with full regio- and stereoselectivity, instead of a carbonyl group reduction. Investigations performed on different α-sulfinylcarbonyl compounds revealed that phenylsilane treatment constitutes a regiospecific method for the desulfinylation of a-sulfinylesters; for corresponding ketones the reaction course depends on the character of the carbonyl group.
PAH-supported tin hydride: A new tin reagent easily removable from reaction mixtures
Gastaldi, Stéphane,Stien, Didier
, p. 4309 - 4311 (2002)
We demonstrate here that a new pyrene-supported tin hydride can be used in radical chemistry. Final products were easily purified by adsorption of the PAH-supported tin side product with activated carbon.
Simple transformation of nitrile into ester by the use of chlorotrimethylsilane
Luo, Fen-Tair,Jeevanandam, Arumugasamy
, p. 9455 - 9456 (1998)
Treatment of nitriles with alcohol and chlorotrimethylsilane at 50°C for 4 h could give esters in fair to good yields. Under similar reaction conditions, intramolecular lactonization via the concomitant nitrile and hydroxy groups in good yield were also demonstrated.
Chemistry of palladium phosphinite (PPh2(OR)) and phosphonite (P(OPh)2(OH)) complexes: Catalytic activity in methoxycarbonylation and Heck coupling reactions
Pryjomska, Iweta,Bartosz-Bechowski, Hubert,Ciunik, Zbigniew,Trzeciak, Anna M.,Ziolkowski, Jozef J.
, p. 213 - 220 (2006)
The new phosphinite and phosphonite complexes (1-8) are very efficient catalysts for the methoxycarbonylation of iodobenzene and Heck cross-coupling of bromobenzene with butyl acrylate. High catalytic activity of these complexes can be explained by their in situ transformations during the reaction, stimulated by the presence of water, acid (HCl) or base (NEt3). Hydrolysis of phosphinite palladium complexes of the form trans-PdCl 2[PPh2(OR)]2 (R = C6F5 2, tBu 3, or O-menthyl 4) results in the formation of the dimeric complex [μ-ClPd(PPh2OH)(PPh2O)]2 5, which is deprotonated by NEt3, producing a polymeric complex of formula [Pd(P(O)PPh2)2]n 8. The reverse reaction, protonolysis of 8 with HCl, leads back to 5 and the monomeric complex 5a. The phosphinite complex PdCl2[PPh2(OBu)]2 1 with a more lipophilic ligand, PPh2(OBu), does not undergo hydrolysis under the same conditions. In the reaction of PdCl2(cod) with P(OPh) 2(OH), the new dimer [μ-ClPd(P(OPh)2OH)(P(OPh) 2O)]2 6 was obtained, whereas reaction of Pd(OAc) 2 with P(OPh)2(OH) leads to the polymeric complex [Pd[P(O)(OPh)2]2]n 7. Protonolysis of 7 with HCl results in the formation of 6. The Royal Society of Chemistry 2006.
