- High yield synthesis of the parent C-unsubstituted calix[4]resorcinarene octamethyl ether
-
Treatment of 2,4-dimethoxybenzyl alcohol with trifluoroacetic acid (TFA, 5% in CHCl3) affords, in almost quantitative yield calix[4]resorcinarene octamethyl ether, which on demethylation and acetylation yields the derived octa-acetate.
- Falana, Olusegun M.,Al-Farhan, Emile,Keehn, Philip M.,Stevenson, Robert
-
-
Read Online
- Nickel catalyzed sustainable synthesis of benzazoles and purines: Via acceptorless dehydrogenative coupling and borrowing hydrogen approach
-
Herein we report nickel-catalyzed sustainable synthesis of a few chosen five-membered fused nitrogen heterocycles such as benzimidazole, purine, benzothiazole, and benzoxazole via acceptorless dehydrogenative functionalization of alcohols. Using a bench stable, easy to prepare, and inexpensive Ni(ii)-catalyst, [Ni(MeTAA)] (1a), featuring a tetraaza macrocyclic ligand (tetramethyltetraaza[14]annulene (MeTAA)), a wide variety of polysubstituted benzimidazole, purine, benzothiazole, and benzoxazole derivatives were prepared via dehydrogenative coupling of alcohols with 1,2-diaminobenzene, 4,5-diaminopyrimidine, 2-aminothiphenol, and 2-aminophenol, respectively. A wide array of benzimidazoles were also prepared via a borrowing hydrogen approach involving alcohols as hydrogen donors and 2-nitroanilines as hydrogen acceptors. A few control experiments were performed to understand the reaction mechanism.
- Chakraborty, Gargi,Guin, Amit Kumar,Mondal, Rakesh,Paul, Nanda
-
p. 7217 - 7233
(2021/08/30)
-
- Synthesis of acyclic and cyclic phosphonates based on substituted 2-hydroxybenzylic alcohols
-
A convenient synthesis of benzylic phosphonates and 2,3-dihydrobenzo[d][1,2]oxaphosphole 2-oxides substituted at the aromatic ring, as well as their precursors, 2-hydroxybenzylic alcohols, from the derivatives of salicylic aldehyde, salicylic acid, and 2-hydroxyacetophenone bearing an additional hydroxy or methoxy group at the para position of the aromatic ring was developed. For the first time, the possibility of selective demethylation of the methoxy group positioned ortho to the methylene phosphonate fragment with retention of the methoxy group at the para position was shown.
- Brel, V. K.,Mikulenkova, E. A.,Mironov, V. F.,Tatarinov, D. A.,Terekhova, N. V.
-
p. 2147 - 2152
(2020/12/09)
-
- On the Necessity of Nucleobase Protection for 2-Thiouracil for Fmoc-Based Pseudo-Complementary Peptide Nucleic Acid Oligomer Synthesis
-
A selection of benzyl-based protecting groups for thiouracil (SU) for the synthesis of pseudo-complementary peptide nucleic acid (PNA) has been evaluated. The 4-methoxybenzyl-protecting group that has found use for SU during Boc-based oligomerization is also suitable for Fmoc-based oligomerization. Furthermore, it is demonstrated that SU protection is unnecessary for the successful synthesis of thiouracil-containing PNA. The new 2-thiothymine (ST) PNA monomer has also been prepared and incorporated into an oligomer and its binding to complementary PNA evaluated.
- Hudson, Robert H.E.,Heidari, Ali,Martin-Chan, Timothy,Park, Gyeongsu,Wisner, James A.
-
p. 13252 - 13261
(2019/11/16)
-
- Novel indole and triazole based hybrid molecules exhibit potent anti-adipogenic and antidyslipidemic activity by activating Wnt3a/β-catenin pathway
-
Obesity and dyslipidemia is the two facet of metabolic syndrome, which needs further attention. Recent studies indicate triazole and indole derivatives have remarkable anti-obesity/antidyslipidemic activity. To harness the above-mentioned potential, a series of novel triazole clubbed indole derivatives were prepared using click chemistry and evaluated for anti-adipogenic activity. Based on the structure-activity relationship, essential functional groups which potentiate anti-adipogenic activity were identified. The lead compound 13m exhibited potent anti-adipogenic activity compared to its parent compounds with the IC-50 value of 1.67 μM. Further evaluation of anti-adipogenic activity was conducted in different cell lines such as C3H10T1/2 and hMSC with positive result. The anti-adipogenic effect of compound 13m was most prominent in the early phase of adipogenesis, which is driven by the G1 to S phase cell cycle arrest during mitotic clonal expansion. The mechanistic study suggests that compound 13m exhibit anti-adipogenic property by activating Wnt3a/β-catenin pathway, a known suppressor of key adipogenic genes PPARγ and C/EBPα. It is noteworthy that the compound 13m also reduced serum triglyceride, LDL and total cholesterol in Syrian Golden hamster model of dyslipidemia. The anti-adipogenic activity of compound 13m can also be correlated with decreased expression of PPARγ and increased expression of β-catenin in epididymal white adipose tissue (eWAT) in vivo. The compound 13m also increased the expression of genes involved in reverse cholesterol transport (RCT) such as PPARα and LXR1α indicating another mechanism by which compound 13m ameliorates dyslipidemia in Syrian Golden hamster model. Overall this study provides a unique perspective into the anti-adipogenic/antidyslipidemic property of triazole and indole hybrids molecules with further scope to increase the anti-adipogenic potency for therapeutic intervention of obesity and metabolic syndrome.
- Rajan, Sujith,Puri, Surendra,Kumar, Durgesh,Babu, Madala Hari,Shankar, Kripa,Varshney, Salil,Srivastava, Ankita,Gupta, Abhishek,Reddy, M. Sridhar,Gaikwad, Anil N.
-
supporting information
p. 1345 - 1360
(2017/11/20)
-
- Transfer hydrogenation and hydration of aromatic aldehydes and nitriles using heterogeneous NiO nanofibers as a catalyst
-
A simple and efficient hydrogen transfer reaction of aldehydes and hydration of nitriles using nickel oxide nanofibers (NiO NFs) as a heterogeneous catalyst is reported. NiO NFs prepared by electrospinning technique was cubic (confirmed by XRD) with an average diameter of 80 nm (obtained from HR-TEM) and utilized as a nanocatalyst for heterogeneous transfer hydrogenation of aromatic aldehydes and hydration of aromatic nitriles. All the reaction products produced with minimum reaction time and maximum yield were confirmed using GC-MS with NIST library. Furthermore, heterogeneity of the catalyst was confirmed with ICP-MS analysis. The as-prepared catalyst was reused for six cycles and was found to be efficient. Hence, the present catalytic synthesis of alcohols and amides may be an economically viable process.
- Thenmozhi,Kadirvelu
-
p. 15572 - 15577
(2018/10/04)
-
- Cobalt complex catalyzed atom-economical synthesis of quinoxaline, quinoline and 2-alkylaminoquinoline derivatives
-
A new phosphine-free Co(ii) complex-catalyzed synthesis of various quinoxalines via dehydrogenative coupling of vicinal diols with both o-phenylenediamines and 2-nitroanilines is reported. This complex was also effective for the synthesis of quinolines. The practical aspect of this catalytic system was revealed by the one-pot synthesis of 2-alkylaminoquinolines.
- Shee, Sujan,Ganguli, Kasturi,Jana, Kalipada,Kundu, Sabuj
-
supporting information
p. 6883 - 6886
(2018/06/26)
-
- A nickel catalyzed acceptorless dehydrogenative approach to quinolines
-
A general, efficient and environmentally benign, one-step synthesis of substituted quinoline derivatives was achieved by acceptorless dehydrogenative coupling of o-aminobenzylalcohols with ketones and secondary alcohols catalyzed by a cheap, earth abundant and easy to prepare nickel catalyst [Ni(MeTAA)], featuring a tetraaza macrocyclic ligand (tetramethyltetraaza[14]annulene (MeTAA)). A wide variety of substituted quinolines were synthesized in high yields starting from readily available o-aminobenzylalcohols and ketones or secondary alcohols. A few controlled reactions were carried out to establish the acceptorless dehydrogenative nature of the reactions.
- Parua, Seuli,Sikari, Rina,Sinha, Suman,Das, Siuli,Chakraborty, Gargi,Paul, Nanda D.
-
p. 274 - 284
(2018/01/12)
-
- Heterobimetallic tin(II) oxido clusters of the type [{Sn6(μ3-O)4(μ3-OCH2R)4} {W(CO)5}4] and [{Sn5(μ3-O)2(μ-OCH2R)4(μ3-OCH2R)2}{Fe(CO)4}2]
-
Reaction of the tin(II) alkoxides bis(2-methoxyphenylmethanolate)tin(II) (1) and bis(2,4-dimethoxyphenylmethanolate)tin(II) (2) with [W(CO)5(thf)] and [Fe2(CO)9], respectively, gave the heterobimetallic tin(II) oxido clusters [{Sn6(μ3-O)4(μ3-OCH2R)4}{W(CO)5}4] [3, R[dbnd6]C6H4(OCH3)-2); 4, R[dbnd6]C6H3(OCH3)2-2,4] and [{Sn5(μ3-O)2(μ-OCH2R)4(μ3-OCH2R)2}{Fe(CO)4}2] [5, R[dbnd6]C6H3(OCH3)2-2,4] which were isolated reproducibly with fair yield as a result of partial hydrolysis in the presence of moisture. The metal oxido clusters are composed of polynuclear tin(II) oxido cages entrapped by arylmethanolato ligands and coordinated to metal carbonyl moieties via lone pairs of electrons at tin. The compounds were analyzed by single crystal X-ray diffraction analysis (1, 4·2THF and 5), elemental analyses, ATR-IR spectroscopy and1H,13C{1H} and119Sn{1H) NMR spectroscopy in solution as well as in solid state.
- Mertens, Lutz,Leonhardt, Christian,Rüffer, Tobias,Toma, Ana,Silvestru, Cristian,Mehring, Michael
-
p. 206 - 213
(2016/11/01)
-
- FeCl3-catalyzed self-cleaving deprotection of methoxyphenylmethyl-protected alcohols
-
4-Methoxyphenylmethyl ethers are widely utilized as alcohol protecting groups. FeCl3 effectively catalyzes the deprotection of methoxyphenylmethyl-type ethers in a self-cleaving manner to produce oligomeric derivatives and alcohols. Remarkably, the highly pure mother alcohols can be obtained without silica gel column chromatography by using the 2,4-dimethoxyphenylmethyl group as a protective group.
- Sawama, Yoshinari,Masuda, Masahiro,Asai, Shota,Goto, Ryota,Nagata, Saori,Nishimura, Shumma,Monguchi, Yasunari,Sajiki, Hironao
-
supporting information
p. 434 - 437
(2015/03/03)
-
- Iron phthalocyanine as new efficient catalyst for catalytic transfer hydrogenation of simple aldehydes and ketones
-
Catalytic transfer hydrogenation (CTH) of various aldehydes and ketones was studied using iron phthalocyanine catalyst, in order to substitute the typically used rare transition metals (Ir, Rh, Ru) with an easily available and less expensive metal. Iron phthalocyanine was found to be an efficient hydrogenation catalyst and its immobilized version was successfully prepared. The immobilized iron phthalocyanine was also active in the CTH reaction of various carbonyl compounds, and it was easy to handle and possible to recycle.
- Bata, Pter,Notheisz, Ferenc,Kluson, Peter,Zsigmond, gnes
-
-
- Use of heterogenized metal complexes in hydrogenation reactions: Comparison of hydrogenation and CTH reactions
-
In the fine chemicals industry the preference for heterogeneous over homogeneous catalysts is well known. However, the activity and selectivity of heterogeneous metal complexes are usually better than those of their homogeneous counterparts. There has, consequently, been an increasing demand for heterogenized metal complexes which combine the advantages of both types of catalyst. In the production of fine chemicals, selectivity is probably its most important property of a catalyst. Chemoselectivity, regioselectivity, and enantioselectivity are very important in the synthesis of fine chemicals. Several examples of hydrogenation with heterogenized metal complexes have been studied, with emphasis on selectivity. Catalytic transfer hydrogenation is also discussed, as an alternative to classical hydrogenation.
- Bata, Peter,Zsigmond, gnes,Gymnt, Mihly,Czegldi, Ambrus,Kluson, Peter
-
p. 9281 - 9294
(2016/01/15)
-
- Pd-catalyzed reduction of aldehydes to alcohols using formic acid as the hydrogen donor
-
Facile and selective reduction of aromatic aldehydes as well as aliphatic aldehydes to alcohols was achieved using formic acid as the hydrogen donor in the presence of a catalytic amount of Pd(OAc)2 and Cy3P. It was found that both hydrogen atoms in the formic acid molecule can serve as the hydride source. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications for the following free supplemental resource(s): Full experimental and spectral details.]
- Wang, Anwei,Yang, Zhiyong,Liu, Jidan,Gui, Qingwen,Chen, Xiang,Tan, Ze,Shi, Ji-Cheng
-
supporting information
p. 280 - 288
(2013/12/04)
-
- Laccase-Mediator System for Alcohol Oxidation to Carbonyls or Carboxylic Acids: Toward a Sustainable Synthesis of Profens
-
By combining two green and efficient catalysts, such as the commercially available enzyme laccase from Trametes versicolor and the stable free radical 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO), the oxidation in water of some primary alcohols to the corresponding carboxylic acids or aldehydes and of selected secondary alcohols to ketones can be accomplished. The range of applicability of bio-oxidation is widened by applying the optimized protocol to the oxidation of enantiomerically pure 2-arylpropanols (profenols) into the corresponding 2-arylpropionic acids (profens), in high yields and with complete retention of configuration.
- Galletti, Paola,Pori, Matteo,Funiciello, Federica,Soldati, Roberto,Ballardini, Alberto,Giacomini, Daria
-
p. 2684 - 2689
(2016/12/23)
-
- Synthesis and in vitro antibacterial activity of gemifloxacin derivatives containing a substituted benzyloxime moiety
-
A series of novel gemifloxacin (GMFX) derivatives containing a substituted benzyloxime moiety with remarkable improvement in lipophilicity were synthesized. The target compounds evaluated for their in vitro antibacterial activity against representative strains. Our results reveal that most of the target compounds have considerable potency against all of the tested Gram-positive strains including MRSA and MRSE (MIC: 90: 1 μg/mL) is 8-fold more active than GMFX, and 2-fold more active than GMFX and moxifloxacin against MRSE clinical isolates (MIC90: 4 μg/mL). Crown Copyright
- Feng, Lianshun,Lv, Kai,Liu, Mingliang,Wang, Shuo,Zhao, Jing,You, Xuefu,Li, Sujie,Cao, Jue,Guo, Huiyuan
-
p. 125 - 136
(2012/11/07)
-
- Reduction of carboxylic acids using esters of benzotriazole as high-reactivity intermediates
-
Herein, we describe a simple and practical protocol for the reduction of carboxylic acids via the in situ formation of hydroxybenzotriazole esters followed by reaction with sodium borohydride to give the corresponding alcohols. The reaction proceeds with excellent yields in the presence of water. Georg Thieme Verlag Stuttgart - New York.
- Morales-Serna, Jose Antonio,Garcia-Rios, Erendira,Bernal, Jorge,Paleo, Ehecatl,Gavino, Ruben,Cardenas, Jorge
-
experimental part
p. 1375 - 1382
(2011/06/19)
-
- Manganese(III) porphyrin covalently bound to sol-gel derived silica (Mn(III) porphyrinosilica): A reusable and green heterogeneous photocatalyst for oxidative decarboxylation of &α-arylacetic acids with H 2O2
-
Manganese(III) (5,10,15,20-tetrakis(2,6-dichlorophenyl)porphyrin)chloride, MnIII(TDCPP)Cl, was chemically (covalently) bound to a silica matrix by a sol-gel method and used as a new reusable heterogeneous photocatalyt for the selective and efficient oxidative decarboxylation of α-arylacetic acids with H2O2 as a mild and clean oxidant at room temperature. The activity of this heterogeneous photocatalytic system is higher than that of a corresponding homogeneous systems and the catalyst can be reused several times without loss of its activity and selectivity.
- Farhadi, Saeid,Zabardasti, Abedien,Rahmati, Mohammad Hosien
-
experimental part
p. 157 - 160
(2011/07/29)
-
- Reduction of aldehydes and ketones with NaBH4/Al 2O3 under solvent-free conditions
-
Aldehydes and ketones are efficiently reduced to the corresponding alcohol using NaBH4 supported onto alumina under solvent free conditions. It was found that the presence of small amount of methanol in reaction media is essential. Chemoselective 1,2-reduction of α, β- unsaturated carbonyl compounds to the corresponding allylic alcohols are also observed.
- Shalbaf
-
experimental part
p. 6761 - 6764
(2012/06/18)
-
- Conformational properties of C2v-symmetrical resorcin[4]arene tetraethers
-
Resorcin[4]arene tetraether derivatives, in which a resorcinol unit and a 1,3-dialkoxybenzene unit are incorporated in an alternating order, were synthesized by the Sc(OTf)3 catalyzed '2 + 2' fragment condensation. The conformational properties were studied using variable temperature 1H-NMR spectroscopy, indicating that the resorcinarenes are flexible at room temperature but frozen in the cone formation at -90°C in CD 2Cl2, and they interconvert between two equivalent cone conformations with an energy barrier of ΔGc? = 10.2-10.5 kcal mol-1. These values are slightly lower than that for the resorcin[4]arene containing four 2-hexylresorcinol units. The cone conformation is stabilized by intramolecular hydrogen bonds between the OH hydrogen and ether oxygen, which is evidenced by the low frequencies (3423-3434 cm-1) of the OH-stretching vibrations in CDCl3 solution. Copyright
- Morikawa, Osamu,Iyama, Eiichi,Oikawa, Tomoyoshi,Kobayashi, Kazuhiro,Konishi, Hisatoshi
-
p. 214 - 218
(2007/10/03)
-
- Selective enzymatic reduction of aldehydes
-
Highly selective enzymatic reductions of aldehydes to the corresponding alcohols was performed using an E. coli JM109 whole cell biocatalyst. A selective enzymatic method for the reduction of aldehydes could provide an eco-compatible alternative to chemical methods. The simplicity, fairly wide scope and the very high observed chemoselectivity of this approach are its most unique features.
- Sello, Guido,Orsini, Fulvia,Bernasconi, Silvana,Di Gennaro, Patrizia
-
p. 365 - 369
(2007/10/03)
-
- Cannizzaro-type disproportionation of aromatic aldehydes to amides and alcohols by using either a stoichiometric amount or a catalytic amount of lanthanide compounds
-
Aromatic aldehydes can be directly converted to the corresponding amides and alcohols in good to excellent yields by the treatment of aromatic aldehydes with lithium amide LiN(SiMe3)2 in the presence of catalytic lanthanide chlorides LnCIs or by the treatment of aromatic aldehydes with a stoichiometric amount of lanthanide amides [(Me3Si)2N]3Ln(μ-Cl) Li(THF)3 at ambient temperature. The effects of solvents, substitutents on the phenyl ring, and lanthanide metals on the reaction have been examined. The mechanism of the disproportionation reaction was proposed based on the experimental results.
- Zhang, Lijun,Wang, Shaowu,Zhou, Shuangliu,Yang, Gaosheng,Sheng, Enhong
-
p. 3149 - 3153
(2007/10/03)
-
- Pd/C-Catalyzed Transfer-Hydrogenation of Benzaldehydes to Benzyl Alcohols Using Potassium Formate as the Selective Hydrogen Donor
-
Aromatic and aliphatic aldehydes are selectively reduced to primary alcohols under mild conditions with potassium formate in the presence of Pd/C catalyst. The high selectivity obtained is attributed due to the presence of the basic potassium bicarbonate generated in situ from the formate salt via the hydrogen transfer process. Molecular hydrogen shows similar activity in the presence of potassium carbonate salts. Ketones did not react under these conditions; therefore, this method is used to separate aldehydes selectively from a mixture of aldehydes and ketones.
- Baidossi, Mubeen,Joshi, Ashutosh V.,Mukhopadhyay, Sudip,Sasson, Yoel
-
p. 643 - 650
(2007/10/03)
-
- An extremely simple, convenient and mild one-pot reduction of carboxylic acids to alcohols using 3,4,5-trifluorophenylboronic acid and sodium borohydride
-
Acyloxyboron intermediates formed in situ from carboxylic acids and 3,4,5-trifluorophenylboronic acids react with sodium borohydride in THF to give alcohols in good to high yields.
- Tale,Patil,Dapurkar
-
p. 3427 - 3428
(2007/10/03)
-
- Arylboronic acid-facilitated selective reduction of aldehydes by tributyltin hydride
-
Aldehydes were selectively reduced in the presence of a ketone with tributyltin hydride (n-Bu3SnH) and arylboronic acids. The double bond of an α-β-unsaturated system was not affected under the reaction conditions.
- Yu,Wang
-
p. 2719 - 2725
(2007/10/03)
-
- Facile and chemoselective reduction of carboxylic acids to alcohols using BOP reagent and sodium borohydride
-
Hydroxybenzotriazolyl esters, formed in situ from carboxylic acids and BOP reagent, react with sodium borohydride in THF to give alcohols in high yields. This method is convenient, rapid and chemoselective, with such functional groups as nitro, halide, nitrile, azido and ester being unaffected.
- McGeary, Ross P.
-
p. 3319 - 3322
(2007/10/03)
-
- The reduction of aromatic aldehydes to hydrocarbons with borohydride exchange resin (BER)-nickel acetate in methanol
-
Aromatic aldehydes were reduced to the corresponding hydrocarbons with borohydride exchange resin (BER)-nickel acetate in methanol in excellent yields.
- Bandgar,Kshirsagar,Wadgaonkar
-
p. 941 - 945
(2007/10/02)
-
- Cobalt(II) chloride hexahydrate-zinc-dimethylformamide-water: An efficient system for reduction of aldehydes to alcohols
-
The system cobalt(II) chloride hexahydrate-zinc-dimethylformamide-water converts aldehydes to the corresponding alcohols at room temperature in excellent yields.
- Baruah, Robindra N.
-
p. 182 - 183
(2007/10/02)
-
- An efficient reduction system - NiCl2·6H2O-Zn/DMF-H2O for conversion of aldehydes to alcohols
-
Aldehydes were efficiently converted to the corresponding alcohols at room temperature, with NiCl2·6H2O-Zn/DMF-H2O system.
- Baruah, Robindra N.
-
p. 5417 - 5418
(2007/10/02)
-
- CHEMOSELECTIVE REDUCTION OF ALDEHYDES WITH ZINC BOROHYDRIDE IN TETRAHYDROFURAN
-
A variety of structurally different aldehydes undergo chemoselective reduction over ketones with zinc borohydride in tetrahydrofuran at -10 deg C to the corresponding alcohols.
- Ranu, Brindaban C.,Chakraborty, Rupak
-
p. 7663 - 7664
(2007/10/02)
-
- DEOXYGENATION OF ALDEHYDES AND KETONES WITH SODIUM CYANOBOROHYDRIDE
-
Treatment of hydroxy-substituted aromatic aldehydes and ketones with sodium cyanoborohydride yields the corresponding methylene compounds under conditions which favor intermediate carbonium ion formation.
- Elliger, Carl A.
-
p. 1315 - 1324
(2007/10/02)
-
