- Impact of variation of the acyl group on the efficiency and selectivity of the lipase-mediated resolution of 2-phenylalkanols
-
By tuning the steric properties of the acyl group to control the efficiency and selectivity of the resolution, 2-phenyl-1-propanol 1a was prepared by lipase-catalysed hydrolysis using a short-chain acyl group, with E-values of up to 66 (ee up to 95%). 2-Phenylbutan-1-ol 1b was similarly resolved (up to 86% ee) using the optimised conditions, while the ester of the more sterically demanding 3-methyl-2-phenylbutan-1-ol 1c proved resistant to enzymatic hydrolysis under these conditions.
- Foley, Aoife M.,Gavin, Declan P.,Joniec, Ilona,Maguire, Anita R.
-
-
Read Online
- New porphyrin-polyoxometalate hybrid materials: Synthesis, characterization and investigation of catalytic activity in acetylation reactions
-
New hybrid complexes based on covalent interaction between 5,10,15,20-tetrakis(4-aminophenyl)porphyrinatozinc(ii) and 5,10,15,20- tetrakis(4-aminophenyl)porphyrinatotin(iv) chloride, and a Lindqvist-type polyoxometalate, Mo6O192-, were prepared. These new porphyrin-polyoxometalate hybrid materials were characterized by 1H NMR, FT IR and UV-Vis spectroscopic methods and cyclic voltammetry. These spectro- and electrochemical studies provided several spectral data for synthesis of these compounds. Cyclic voltammetry showed the influence of the polyoxometalate on the redox process of the porphyrin ring. The catalytic activity of tin(iv)porphyrin-hexamolybdate hybrid material was investigated in the acetylation of alcohols and phenols with acetic anhydride. The reusability of this catalyst was also investigated.
- Araghi, Mehdi,Mirkhani, Valiollah,Moghadam, Majid,Tangestaninejad, Shahram,Mohammdpoor-Baltork, Iraj
-
-
Read Online
- Polystyrene-bound electron-deficient tin(IV) porphyrin: A new, highly efficient, robust and reusable catalyst for acetylation of alcohols and phenols with acetic anhydride
-
In the present work, tetrakis(p-aminophenyl)porphyrinatotin(IV) trifluoromethanesulfonate, [SnIV(TNH2PP)(OTf) 2], supported on chloromethylated polystyrene was prepared and characterized by elemental analysis, FT IR and diffuse reflectance UV-Vis spectroscopic methods. This new heterogenized catalyst was used for acetylation of alcohols and phenols with acetic anhydride in short reaction times and high yields. The catalyst is of high reusability and stability in the acetylation reactions and was recovered several times without loss of its initial activity and catalyst leaching.
- Moghadam, Majid,Tangestaninejad, Shahram,Mirkhani, Valiollah,Mohammadpoor-Baltork, Iraj,Gharaati, Shadab
-
-
Read Online
- A new mechanism of enantioselectivity toward chiral primary alcohol by lipase from Pseudomonas cepacia
-
The stereo-recognition of chiral primary alcohols by lipase from Pseudomonas cepacia was found to deviate from earlier observations. Enantioselectivity toward 14 pairs of chiral primary alcohol esters by this lipase was dependent on the existence of an Onon-α(oxygen at non-α-position of the acyloxy group) in the alcohol moiety, and decreased as the size of the acyl moiety increased. Chemical modification on the lipase and molecular dynamics simulations indicated that Tyr29located within the catalytic cavity forms a hydrogen bond with the Onon-αof the preferred enantiomer of the primary alcohol ester. However, a larger acyl moiety suffered stronger hindrance from the catalytic cavity wall of the lipase, pushing the Onon-αaway from Tyr29, and thus weakening the stereo-recognition.
- Meng, Xiao,Guo, Li,Xu, Gang,Wu, Jian-Ping,Yang, Li-Rong
-
-
Read Online
- Lipase-catalyzed hydrolysis of some racemic 1-acetoxy-2-arylpropanes
-
Racemic 1-acetoxy-2-phenylpropane (12) and 1-acetoxy-2-(2- naphthyl)propane (33) were hydrolyzed with lipase at 35-36°C for 2 and 24 h to give predominantly (S)-2-phenyl-1-propanol (11) and (S)-2-(2-naphthyl)-1- propanol (32), respectively. However, racemic 1-acetoxy-2-(1-naphthyl)propane (25) was recovered intact even when the reaction was carried out for 240 h. On the other hand, the enantioselectivities towards racemic 2-phenyl (16), 2- (p-tolyl) (20), 2-(1-naphthyl) (28), and 2-(2-naphthyl) (36) derivatives of 1-acetoxy-2-propanol were very low.
- Matsumoto,Takeda,Iwata,Sakamoto,Ishida
-
-
Read Online
- Rhodium-Catalyzed Reductive Esterification Using Carbon Monoxide as a Reducing Agent
-
Carbon monoxide used to have a limited number of applications in organic chemistry, but it gradually increases its role as a mild and selective reducing agent. It can be applied for the carbon–heteroatom single bond formation via the reductive addition of hydrogen-containing nucleophiles to carbonyl compounds. In this paper, rhodium-catalyzed reductive esterification is described, and a comparative study of the rhodium and ruthenium catalysis in the reductive addition reactions is provided. Rhodium performs better on highly nucleophilic substrates and ruthenium is better for compounds with less nucleophilicity.
- Ostrovskii, Vladimir S.,Runikhina, Sofiya A.,Afanasyev, Oleg I.,Chusov, Denis
-
supporting information
p. 4116 - 4121
(2020/07/13)
-
- Cycloaddition of CO2 with epoxides and esterification reactions using the porous redox catalyst Co-POM@MIL-101(Cr)
-
The catalytic activity of the recently reported Co-POM@MIL-101(Cr) composite, synthesized from K5[CoW12O40] (Co-POM) and chromium(iii) terephthalate (MIL-101), was studied in the solvent-free cycloaddition of CO2 with epoxides and esterification of acetic acid with various alcohols. The materials containing varying amounts of Co-POM were synthesized using a one-pot HF-free method in a "bottle around ship" strategy. The material was thoroughly characterized using several methods such as powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and electron paramagnetic resonance spectroscopy (EPR). Temperature programmed desorption (TPD) of NH3 and CO2, and the CO2 adsorption capacity (adsorption isotherms) were used to study the acid-base properties of the materials. The combination of the electron-transfer character of Co(iii)-POM and ordered mesopores in MIL-101(Cr) creates an efficient catalytic system with mild conditions (90 °C and 20 bar CO2 pressure) for solvent-free cycloaddition of CO2 to various epoxides. Esterification of acetic acid with alcohols was also carried out using the Co-POM@MIL-101 catalysts and high yields were achieved for different alcohols. The catalysis experiments also clearly show that the active site in this heterogeneous catalyst is the Co(iii) center in the Keggin anion structure. It presumably conducts both the cycloaddition of CO2 to epoxides and the esterification reaction via an outer-sphere electron transfer mechanism using the Co(iii)/Co(ii) redox pair. The heterogeneous Co-POM@MIL-101 catalysts were separated by simple filtration and reused five times in the cycloaddition of CO2 with styrene epoxide and seven times for the esterification of acetic acid with benzyl alcohol with negligible leaching of Co-POM and no considerable loss of activity.
- Marandi, Afsaneh,Bahadori, Mehrnaz,Tangestaninejad, Shahram,Moghadam, Majid,Mirkhani, Valiollah,Mohammadpoor-Baltork, Iraj,Frohnhoven, Robert,Mathur, Sanjay,Sandleben, Aaron,Klein, Axel
-
p. 15585 - 15595
(2019/10/19)
-
- P4VPy–CuO nanoparticles as a novel and reusable catalyst: application at the protection of alcohols, phenols and amines
-
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.
- Shirini, Farhad,Fallah-Shojaei, Abdollah,Abedini, Masoumeh,Samavi, Laleh
-
p. 1699 - 1712
(2016/07/27)
-
- Polystyrene trimethyl ammonium chloride impregnated Rh(0) (Rh@PMe3NCl) as a catalyst and methylating agent for esterification of alcohols through selective oxidation of methanol
-
Rhodium(0) nanoparticle (NP)-impregnated polystyrene trimethyl ammonium chloride (PMe3NCl) resin (Rh@PMe3NCl) under basic conditions acts as a cross-dehydrogenative coupling-methylating (CDCM) agent for the selective oxidation of methanol and its in situ reaction with benzyl/alkyl alcohols allowing methyl group transfer for acetate ester synthesis in a tandem approach. The redox property of methanol which restricts the oxidation of benzyl/alkyl alcohols for product formation is critically investigated.
- Guha, Nitul Ranjan,Bhattacherjee, Dhananjay,Das, Pralay
-
p. 2575 - 2580
(2015/06/30)
-
- L-pyrrolidine-2-carboxylic acid-4-hydrogen sulfate (supported on silica gel) as a new and efficient catalyst for acylation of alcohols, phenols and amines under solvent-free conditions
-
In the present work, L-pyrrolidine-2-carboxylic acid-4-hydrogen sulfate, supported on silica gel was prepared and characterized by Mass spectroscopy, 1H NMR, 13CNMR, FT IR and elemental analysis (CHN) methods. This heterogenized catalyst can be used as an efficient catalyst for the acylation of alcohols, phenols, and amines with acetic anhydride under mild and solvent-free conditions. Simple work-up, stability of the catalyst, nontoxicity and good to high yields are the advantages of this work.
- Hajjami, Maryam,Ghorbani-Choghamarani, Arash,Khani, Zahra
-
p. 324 - 329
(2013/07/26)
-
- Enhancement of activity and stability of lipase by microemulsion-based organogels (MBGs) immobilization and application for synthesis of arylethyl acetate
-
Lipase from Candida rugosa (CRL) was immobilized in microemulsion-based organogels (MBGs) and subsequently applied in large scale synthesis of arylethyl acetate in organic solvents as a more stable and efficient catalyst. Various reaction parameters (solvent, temperature, substrate concentration) were investigated for enhancement of ester production. Thermal and operational stabilities were improved compared with free CRL showing its potential for continuous applications. They were more stable at 50-60 °C and showed good recovery activity, which retained 70% of their initial activity after 16 recycles in organic media and remained constant at that level thereafter. Moreover, the immobilized lipase can maintain high catalytic activity in a variety of organic solvents, while free lipase was easily inactivated in polar solvent. A series of alcohols with different substitution groups were successfully applied in CRL MBGs-catalyzed transesterification, affording higher conversions than those with the free enzyme.
- Zhang, Wei-Wei,Wang, Na,Zhou, Yu-Jie,He, Ting,Yu, Xiao-Qi
-
experimental part
p. 65 - 71
(2012/07/13)
-
- H6GeMo10V2O40·16H 2O nanoparticles prepared by hydrothermal method: A new and reusable heteropoly acid catalyst for highly efficient acetylation of alcohols and phenols under solvent-free conditions
-
A new Keggin-type heteropoly acid, namely decamolybdodivanadogermanic acid (H6GeMo10V2O40·16H 2O), with nanosized particles (5-8 nm), has been synthesized by a hydrothermal method and characterized by elemental analysis, thermogravimetric analysis (TGA), powder X-ray diffractometry (XRD), Fourier-transform infrared spectroscopy (FTIR), UV-Visible spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and potentiometric titration. H6GeMo10V2O40·16H 2O revealed high catalytic activity for acetylation of various alcohols and phenols with acetic anhydride at room temperature (298 ± 2 K) and under solvent-free conditions. The catalyst can be easily recovered and used repeatedly for five cycles with a slight loss of activity. The catalytic activity of H6GeMo10V2O40· 16H2O was higher than that of other Keggin-type heteropoly acids, such as H3PW12O40, H3PMo 12O40 and H4SiW12O40.
- Farhadi, Saeid,Zareisahamieh, Reza,Zaidi, Masoumeh
-
experimental part
p. 1323 - 1332
(2012/04/04)
-
- Electron-deficient [TiIV(salophen)(OTf)2]: A new and highly efficient catalyst for the acetylation of alcohols and phenols with acetic anhydride
-
In the present work, a highly efficient method for acetylation of alcohols and phenols with acetic anhydride catalyzed by high-valent [Ti IV(salophen)(OTf)2] is reported. Under these conditions, primary, secondary and tertiary alcohols as well as phenols were acetylated with short reaction times and high yields. The catalyst was reused several times without loss of its catalytic activity.
- Yadegari, Maryam,Moghadam, Majid,Tangestaninejad, Shahram,Mirkhani, Valiollah,Mohammadpoor-Baltork, Iraj
-
experimental part
p. 2237 - 2243
(2011/10/03)
-
- Efficient acetylation of alcohols, phenols, and amines catalyzed by melamine trisulfonic acid (MTSA)
-
Melamine trisulfonic acid (MTSA) was easily prepared by the reaction of melamine with neat chlorosulfonic acid at room temperature. This reagent can be used as an efficient catalyst for the acetylation of alcohols, phenols, and amines with Ac2O under mild and completely heterogeneous reaction conditions.
- Shirini, Farhad,Zolfigol, Mohammad Ali,Aliakbar, Ali-Reza,Albadi, Jalal
-
experimental part
p. 1022 - 1028
(2010/05/18)
-
- A mild and efficient method for the methoxymethylation and acetylation of alcohols promoted by benzyltriphenylphosphonium tribromide
-
A mild and efficient method for the conversion of alcohols to their corresponding methoxymethyl ethers and acetates using benzyltriphenylphosphonium tribromide (BTPTB) as catalyst is described. All reactions were performed under completely heterogeneous reaction conditions in good to high yields.
- Shirini, Farhad,Imanzadeh, Gholam Hossein,Mousazadeh, Seyyed Ali Reza,Mohammadpoor-Baltork, Iraj,Abedin, Masoumeh
-
experimental part
p. 1187 - 1190
(2011/10/05)
-
- Saccharinsulfonic acid: An efficient and recyclable catalyst for acetylation of alcohols, phenols, and amines
-
Saccharinsulfonic acid is an efficient catalyst of the protection of alcohols, phenols, and amines with acetic anhydride. All reactions were performed under mild and completely heterogeneous reaction conditions. with excellent yields.
- Shirini, Farhad,Zolfigol, Mohammad Ali,Abedini, Masoumeh
-
experimental part
p. 1495 - 1498
(2010/06/19)
-
- Baeyer-Villiger monooxygenase-catalyzed kinetic resolution of racemic α-alkyl benzyl ketones: enzymatic synthesis of α-alkyl benzylketones and α-alkyl benzylesters
-
The application of three BVMOs for the enantioselective oxidation of 3-phenylbutan-2-ones with different substituents in the aromatic moiety is described. By choosing the appropriate biocatalyst and substrate combination, chiral ketones and esters can be obtained with excellent enantiopurities. This methodology could also be applied to the resolution of racemic α-alkyl benzylketones with longer alkyl chains as well as with two substituted α-substituted benzylacetones. A kinetic analysis revealed that the BVMOs studied effectively convert all tested compounds showing that the enzymes are tolerant towards the substrate structure while being highly enantioselective. These properties render BVMOs as valuable biocatalysts for the preparation of compounds with high interest in organic synthesis.
- Rodriguez, Cristina,Gonzalo, Gonzalo de,Torres Pazmino, Daniel E.,Fraaije, Marco W.,Gotor, Vicente
-
experimental part
p. 1168 - 1173
(2009/10/02)
-
- Polymer-supported gadolinium triflate as a convenient and efficient Lewis acid catalyst for acetylation of alcohols and phenols
-
A polymer-supported gadolinium triflate (CMPS-IM-Gd) catalyst was prepared from chloromethyl polystyrene (CMPS) resin using a simple and convenient procedure. This polymeric catalyst was used as an efficient Lewis acid catalyst for the acetylation of various alcohols and phenols with acetic anhydride, affording high yields under mild conditions. The reaction was completed in a short period of time with small amounts of the catalyst. The catalyst was reused over 10 times without any significant loss of its catalytic activity.
- Yoon, Hyo-Jin,Lee, Sang-Myung,Kim, Jong-Ho,Cho, Hong-Jun,Choi, Jung-Woo,Lee, Sang-Hyeup,Lee, Yoon-Sik
-
p. 3165 - 3171
(2008/09/20)
-
- N, O-ligand accelerated zinc-catalyzed transesterification of alcohols with vinyl esters
-
N-Phenyldiethanolamine (1f) is an efficient ligand for zinc-catalyzed transesterification of alcohols with vinyl acetate (R3 = Me) at room temperature. In the case of using other vinyl esters (R3 = Et, n-Pr, Ph), the corresponding products were easily obtained in the presence of pyridine-type ligand 2 instead of aminoalcohol 1f.
- Mino, Takashi,Hasegawa, Tae,Shirae, Yoshiaki,Sakamoto, Masami,Fujita, Tsutomu
-
p. 4389 - 4396
(2008/02/13)
-
- Efficient acetylation and formylation of alcohols in the presence of Zr(HSO4)4
-
Acetylation and formylation of alcohols with acetic and formic acids have been carried out in the presence of catalytic amounts of Zr(HSO 4)4 under mild and heterogeneous conditions.
- Shirini, Farhad,Zolfigol,Safari
-
p. 154 - 156
(2007/10/03)
-
- A mild and efficient method for the acetylation of alcohols
-
The acetylatioh of alcohols has been carried out efficiently in the presence of a catalytic amount of Zr(HSO4)4. All reactions are performed at room temperature and under heterogeneous conditions in good to high yields.
- Shirini,Zolfigol,Safari
-
p. 201 - 203
(2007/10/03)
-
- Transesterification of various alcohols with vinyl acetate under mild conditions catalyzed by diethylzinc using N-substituted diethanolamine as a ligand
-
Commercially available, inexpensive N-phenyldiethanolamine (6) is an efficient ligand for zinc-catalyzed transesterification. The use of 6/Et 2Zn for reactions between various alcohols and vinyl acetate at room temperature produced the desired products in good yields.
- Shirae, Yoshiaki,Mino, Takashi,Hasegawa, Tae,Sakamoto, Masami,Fujita, Tsutomu
-
p. 5877 - 5879
(2007/10/03)
-
- Al(HSO4)3 as an efficient catalyst for the acetylation of alcohols in solution and under solvent free conditions
-
Alcohols are acetylated in a mild, clean, and efficient reaction with acetic anhydride in the presence of a catalytic amount of Al(HSO 4)3 in solution and under solvent free conditions. All reactions were performed at room temperature in good to high yields. Springer-Verlag 2003.
- Shirini, Farhad,Zolfigol, Mohammad A.,Abedini, Masoumeh
-
p. 279 - 282
(2007/10/03)
-
- Poly(ethylene glycol)-lipase complexes that are highly active and enantioselective in ionic liquids.
-
Lipase-catalyzed alcoholysis between vinyl acetate and 2-phenyl-1-propanol was investigated in dialkylimidazolium-based ionic liquids. Although native lipase powder exhibited very low activity in an ionic liquid, forming a poly(ethylene glycol)(PEG)-lipase complex improved the lipase activity in the ionic liquid. The activity of the PEG-lipase complex was higher in ionic liquids than in common organic solvents (n-hexane, isooctane and dimethylsulfoxide). Fluorescence measurements using 4-aminophthalimide revealed that the ionic liquids were more hydrophilic than the organic solvents used for non-aqueous enzymology. A kinetic study of lipase-catalyzed alcoholysis in an ionic liquid ([Bmim][PF6]) revealed that the Michaelis constant (Km) for 2-phenyl-1-propanol in the ionic liquid was half that in n-hexane, suggesting that the ionic liquid stabilized the enzyme-substrate complex. Finally, we carried out enantioselective alcoholysis of 1-phenylethanol in ionic liquids employing the PEG-lipase complex, and obtained high enantioselectivity, comparable to that in n-hexane.
- Maruyama, Tatsuo,Yamamura, Hiroshi,Kotani, Takahiro,Kamiya, Noriho,Goto, Masahiro
-
p. 1239 - 1244
(2007/10/03)
-
- Acetylation and formylation of alcohols in the presence of silica sulfuric acid
-
Alcohols are converted to esters in a mild, clean, and efficient reaction with acetic and formic acids in the presence of silica sulfuric acid. All reactions were performed under mild and completely heterogeneous conditions in refluxing n-hexane.
- Shirini, Farhad,Zolfigol, Mohammad Ali,Mohammadi, Kamal
-
p. 1617 - 1621
(2007/10/03)
-
- THE EFFECT OF para-SUBSTITUENTS ON THE CONFORMATIONAL BEHAVIOUR OF AROMATIC SIDECHAINS
-
Proton nmr data are reported for some 2-aryl-1-propyl methyl esters, 2-aryl-1-propyl acetates and trifluoroacetates, 2-aryl-1-propanols and 4-aryl-2,2-dimethylpentanes.The vicinal coupling constants show that there is an increasing population of gauche Aryl/OR rotamers in the first three series (R = Me, R = COMe and R = COCF3) as electron donor groups on the aromatic ring are replaced by electron withdrawing groups.The results are ascribed to a gauche Aryl --- O interaction, the possible origins of which are discussed.
- Cook, Michael J.,Khan, Tauqeer A.,Nasri, Khalida
-
p. 249 - 258
(2007/10/02)
-