5876-92-6Relevant articles and documents
Synthesis and characterization of 4-chlorobutyl ester of 5-(8-carboxyl-1-naphthyl)-10,15,20-triphenyl-porphyrin and its zinc complex
Liu, Huan,Ou, Caifen,Ma, Ben,Hu, Chuanjiang
, p. 597 - 602 (2017)
In the presence of Br?nsted–Lowry acids (phenol or dry HCl), the acyl chloride, which was obtained by the reaction between 5-(8-carboxyl-1-naphthyl)-10,15,20-triphenyl-porphyrin (CNTPP) and oxalyl chloride, reacted with tetrahydrofuran and led to the 4-chlorobutyl ester, P1, as the result of the acylative cleavage. P1 and its zinc complex [ZnP1] have been characterized by1H NMR. The structure of [ZnP1] was obtained by X-ray crystallography. Zinc is coordinated by four pyrrole nitrogens. The 8-position substituent, a 4- chlorobutyl ester group, lies above the porphyrin plane.
Aqueous microdroplets containing only ketones or aldehydes undergo Dakin and Baeyer-Villiger reactions
Gao, Dan,Jin, Feng,Lee, Jae Kyoo,Zare, Richard N.
, p. 10974 - 10978 (2019/12/28)
The Dakin and Baeyer-Villiger (BV) oxidation reactions require addition of peroxides as oxidants and an acid or a base as a catalyst. Reaction times range from hours to days to obtain target products. Previously, we reported that hydrogen peroxide (H2O2) is spontaneously generated in water microdroplets without any added chemicals or applied electrical potential. Here, we report that the Dakin and BV reactions occur in modest yields within milliseconds in aqueous microdroplets at room-temperature without the addition of external peroxides and catalysts. H2O2 generation is the result of the special environment of the microdroplet surface, which promotes water autoionization. We find that increasing the content of water and decreasing the droplet size improve the product yield of the Dakin and BV reactions, supporting the contention that the amount of H2O2 generated in aqueous microdroplets could induce the two reactions and the reactions occur at or near the air-water interface of the microdroplet surface.
Selective Monoacylation of Diols and Asymmetric Desymmetrization of Dialkyl meso-Tartrates Using 2-Pyridyl Esters as Acylating Agents and Metal Carboxylates as Catalysts
Hashimoto, Yuki,Michimuko, Chiaki,Yamaguchi, Koki,Nakajima, Makoto,Sugiura, Masaharu
supporting information, p. 9313 - 9321 (2019/08/12)
With 2-pyridyl benzoates as acylating agents and Zn(OAc)2 as a catalyst, 1,2-diols, 1,3-diols, and catechol were selectively monoacylated. Furthermore, the highly enantioselective desymmetrization of meso-tartrates was achieved for the first time, utilizing 2-pyridyl esters and NiBr2/AgOPiv/Ph-BOX in CH3CN or CuCl2/AgOPiv/Ph-BOX in EtOAc catalyst systems (up to 96% ee). The latter catalyst system was also effective for the kinetic resolution of dibenzyl dl-tartrate.
Direct hydroxylation of benzene and aromatics with H2O2 catalyzed by a self-assembled iron complex: Evidence for a metal-based mechanism
Capocasa, Giorgio,Olivo, Giorgio,Barbieri, Alessia,Lanzalunga, Osvaldo,Di Stefano, Stefano
, p. 5677 - 5686 (2017/12/07)
An iminopyridine Fe(ii) complex, easily prepared in situ by self-assembly of cheap and commercially available starting materials (2-picolylaldehyde, 2-picolylamine, and Fe(OTf)2 in a 2 : 2 : 1 ratio), is shown to be an effective catalyst for the direct hydroxylation of aromatic rings with H2O2 under mild conditions. This catalyst shows a marked preference for aromatic ring hydroxylation over lateral chain oxidation, both in intramolecular and intermolecular competitions, as long as the arene is not too electron poor. The selectivity pattern of the reaction closely matches that of electrophilic aromatic substitutions, with phenol yields and positions dictated by the nature of the ring substituent (electron-donating or electron-withdrawing, ortho-para or meta-orienting). The oxidation mechanism has been investigated in detail, and the sum of the accumulated pieces of evidence, ranging from KIE to the use of radical scavengers, from substituent effects on intermolecular and intramolecular selectivity to rearrangement experiments, points to the predominance of a metal-based SEAr pathway, without a significant involvement of free diffusing radical pathways.
Synthesis of industrially important aromatic and heterocyclic ketones using hierarchical ZSM-5 and Beta zeolites
Kore, Rajkumar,Srivastava, Rajendra,Satpati, Biswarup
, p. 129 - 141 (2015/09/28)
Hierarchical ZSM-5 and Beta zeolites were investigated in the synthesis of wide range of industrially important aromatic/heterocyclic ketones by Friedel-Crafts acylation and benzoylation reactions. For comparative study, conventional ZSM-5 and Beta, and amorphous mesoporous Al-MCM-41 were investigated. Hierarchical zeolites were prepared by multi-ammonium structure directing agents whereas conventional zeolites were prepared by mono-ammonium structure directing agents. Among the catalysts investigated in this study, hierarchical Beta exhibited the highest reactant conversion in the acylation and benzoylation reactions. In this study, the systematic assessment of the catalytic activity of acid catalysts for wide range of aromatic and heterocyclic compounds is shown under one umbrella. To the best of our knowledge, these reactions over hierarchical zeolites (ZSM-5 and Beta) are reported here for the first time. Structure activity relationship is explained based on the physico-chemical properties, molecular size, reactivity of reactants, and reaction mechanism. Catalysts can be easily recovered and reused with negligible loss in the catalytic activity.
Selective monobenzoylation of 1,2- and 1,3-diols catalyzed by Me 2SnCl2 in water (organic solvent free) under mild conditions
Muramatsu, Wataru,William, Julius M.,Onomura, Osamu
experimental part, p. 754 - 759 (2012/02/15)
We have developed an efficient method for selective monobenzoylation of 1,2- and 1,3-diols in water catalyzed by Me2SnCl2. Treatment of 1,2- and 1,3-diols with benzoyl chlorides, DMT-MM, and potassium carbonate in the presence of a catalytic amount of Me2SnCl 2 and DMAP in water at room temperature gave monobenzoates in up to 97% yield.
HF-Pyridine: A versatile promoter for monoacylation/sulfonylation of phenolic diols and for direct conversion of t-butyldimethylsilyl ethers to the corresponding acetates
Michigami, Kyosuke,Yoshimoto, Kazuya,Hayashi, Masahiko
scheme or table, p. 138 - 139 (2012/03/09)
Monoacylation and trifluoromethanesulfonylation of phenolic diols were achieved by the aid of HF-pyridine, whereas diacylation occurred with pyridine alone. Furthermore, HF-pyridine was found to promote the direct conversion of t-butyldimethylsilyl ethers to the corresponding acetates.
Selective mono-acylation of 1,2- and 1,3-diols using (α,α- difluoroalkyl)amines
Wakita, Natsumi,Hara, Shoji
experimental part, p. 7939 - 7945 (2010/10/19)
In the reaction of N,N-diethyl-α,α-difluorobenzylamine (DFBA) with 1,2- or 1,3-diols, selective mono-benzoylation occurs to afford mono-esters of the diols in good yield. The reaction is completed under mild conditions in a short reaction time. Further, prim-, sec-, and tert-diols and catechol can be converted to the corresponding mono-benzoates. DFBA is used for the protection of the hydroxy group in sugars. The selective mono-nicotinylation, formylation and pivaloylation of diols are also performed by using the corresponding difluoroalkylamines.
Spontaneous resolution among chiral glycerol derivatives: crystallization features of ortho-alkoxysubstituted phenyl glycerol ethers
Bredikhin, Alexander A.,Bredikhina, Zemfira A.,Zakharychev, Dmitry V.,Konoshenko, Larisa V.
, p. 1964 - 1970 (2008/02/13)
Five chiral arylglycerol ethers 2-R-C6H4-O-CH2CH(OH)CH2OH (R = OMe, OEt, OPrn, OPri, OBut) have been prepared in racemic and enantiopure form. The melting points and enthalpies of fusion of every species were measured by differential scanning calorimetry. Binary phase diagrams were reconstructed for the whole family, the entropies of the mixing of the enantiomers in the liquid state, and Gibbs free energy of formation of the racemic compound, as well as Pettersson i-values were derived from the thermal data. The differences in the phase behavior of the investigated compounds were associated with the conformations of the alkoxy fragments.
CONDENSED RING COMPOUND AND USE THEREOF
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Page/Page column 95, (2010/11/08)
The present invention relates to a compound of formula (I) (wherein all symbols have the same meanings as described hereinbefore). The compound antagonizes cysLT2 and therefore, it is useful as an agent for the prevention and/or treatment of respiratory diseases such as bronchial asthma, bronchial asthma, chronic obstructive pulmonary disease, pneumonectasia, chronic bronchitis, pneumonia (e.g. interstitial pneumonitis etc.), severe acute respiratory syndrome (SARS), acute respiratory distress syndrome (ARDS), allergic rhinitis, sinusitis (e.g. acute sinusitis, chronic sinusitis, etc.), and the like, or as an expectorant or antitussives.
