- Easy kinetic resolution of some β-amino alcohols by Candida antarctica lipase B catalyzed hydrolysis in organic media
-
Herein, we present an easy and eco-friendly pathway to obtain some enantiomerically enriched β-amino alcohols using essentially as β-blockers. The enzymatic hydrolysis is conducted in hydrophobic organic media, assisted by sodium carbonate and CAL-B. We describe a new and effective procedure in terms of the chemo- and enantioselectivity, which allows for the formation of both enantiomers: the 2-acetamido-1-arylacetates and 2-acetamido-1-arylethanols were obtained with high ee values (up to >99%), while the selectivities reached E >200. The obtained results show a high CAL-B affinity toward the deacylation of the 2-acetamido-1-arylacetates compared to the acylation one. The structure of the 2-acetamido-1-arylacetates had a significant influence on both reactivity and selectivity of the CAL-B catalyzed deacylation. A multigram scale O-deacylation of racemic 2-acetamido-1-phenylacetate has been carried out, giving access both enantiomers with high enantiomeric purity and good isolated chemical yields.
- Alalla, Affef,Merabet-Khelassi, Mounia,Riant, Olivier,Aribi-Zouioueche, Louisa
-
supporting information
p. 1253 - 1259
(2016/11/23)
-
- Direct catalytic synthesis of unprotected 2-amino-1-phenylethanols from alkenes by using iron(II) phthalocyanine
-
Aryl-substituted amino alcohols are privileged scaffolds in medicinal chemistry and natural products. Herein, we report that an exceptionally simple and inexpensive FeII complex efficiently catalyzes the direct transformation of simple alkenes into unprotected amino alcohols in good yield and perfect regioselectivity. This new catalytic method was applied in the expedient synthesis of bioactive molecules and could be extended to aminoetherification.
- Legnani, Luca,Morandi, Bill
-
supporting information
p. 2248 - 2251
(2016/02/18)
-
- Green synthesis of benzamides in solvent- and activation-free conditions
-
Herein, we describe a clean and ecocompatible pathway for both N-benzoylation and N-acetylation of anilines, amines, diamines, and aminoalcohols using three enol esters with good yields. We have improved the use of vinyl benzoate for the direct introduction of a benzamido-moiety under solvent- and activation-free conditions. The recovered amides are easily isolated by crystallization. Copyright
- Alalla, Affef,Merabet-Khelassi, Mounia,Aribi-Zouioueche, Louisa,Riant, Olivier
-
supporting information
p. 2364 - 2376
(2014/07/22)
-
- Synthesis of new N-acryl-1-amino-2-phenylethanol and N-acyl-1-amino-3- aryloxypropanols and evaluation of their antihyperlipidemic, LDL-oxidation and antioxidant activity
-
As a part of our drug discovery program, we identified an alkaloidal amide i.e. Aegeline (V) isolated from the leaves of Aegle marmelos as a dual acting agent (antihyperlipidemic and antihyperglycemic). In continuation of this program, we synthesized new N-acyl-1-amino-2-alcohols (N-acrylated-1-amino-2- phenylethanol and N-acylated-1-amino-3-aryloxypropanols) via Ritter reaction and screened for their in-vivo antihyperlipdemic activity in Triton induced hyperlipidemia model, LDL-oxidation and antioxidant activity. Compounds 3, 11 and 13 showed good antihyperlipidemic activity, LDL-oxidation as well as antioxidant activity and comparable activity with marketed antidyslipidemic drug.
- Sarkar, Satinath,Sonkar, Ravi,Bhatia, Gitika,Tadigoppula, Narender
-
p. 135 - 144
(2014/05/20)
-
- Steric vs. electronic effects in the Lactobacillus brevis ADH-catalyzed bioreduction of ketones
-
Lactobacillus brevis ADH (LBADH) is an alcohol dehydrogenase that is commonly employed to reduce alkyl or aryl ketones usually bearing a methyl, an ethyl or a chloromethyl as a small ketone substituent to the corresponding (R)-alcohols. Herein we have tested a series of 24 acetophenone derivatives differing in their size and electronic properties for their reduction employing LBADH. After plotting the relative activity against the measured substrate volumes we observed that apart from the substrate size other effects must be responsible for the activity obtained. Compared to acetophenone (100% relative activity), other small substrates such as propiophenone, α,α, α-trifluoroacetophenone, α-hydroxyacetophenone, and benzoylacetonitrile had relative activities lower than 30%, while medium-sized ketones such as α-bromo-, α,α-dichloro-, and α,α-dibromoacetophenone presented relative activities between 70% and 550%. Moreover, the comparison between the enzymatic activity and the obtained final conversions using an excess or just 2.5 equiv. of the hydrogen donor 2-propanol, denoted again deviations between them. These data supported that these hydrogen transfer (HT) transformations are mainly thermodynamically controlled. For instance, bulky α-halogenated derivatives could be quantitatively reduced by LBADH even employing 2.5 equiv. of 2-propanol independently of their kinetic values. Finally, we found good correlations between the IR absorption band of the carbonyl groups and the degrees of conversion obtained in these HT processes, making this simple method a convenient tool to predict the success of these transformations. The Royal Society of Chemistry.
- Rodriguez, Cristina,Borzecka, Wioleta,Sattler, Johann H.,Kroutil, Wolfgang,Lavandera, Ivan,Gotor, Vicente
-
supporting information
p. 673 - 681
(2014/01/06)
-
- Thioacids mediated selective and mild N-acylation of amines
-
N-Acylated amines are ubiquitous in nature. Selective N-acylation at neutral conditions remains a key area of interest. Here we are reporting the copper sulfate-mediated highly selective, mild, and rapid N-acylation of various aliphatic and aromatic amines using thioacids in methanol at neutral conditions. All N-acylated products of primary and secondary amines were isolated in good to excellent yields. This method is found to be highly selective for the amines and not sensitive to other functional groups such as phenols, alcohols, and thiols. The simple workup, high yields, and high selectivity of this reaction can be an attractive alternative to those of the existing acyl halide- and acid anhydride-mediated N-acylation reactions.
- Mali, Sachitanand M.,Bhaisare, Rupal D.,Gopi, Hosahudya N.
-
p. 5550 - 5555
(2013/07/25)
-
- Isopropenyl acetate, a remarkable, cheap and acylating agent of amines under solvent- and catalyst-free conditions: A systematic investigation
-
Isopropenyl acetate was proved to be an efficient reagent for acetylation of amine in the absence of solvent and catalyst. The corresponding acetamides were obtained in very high yields without any purification.
- Pelagalli, Romina,Chiarotto, Isabella,Feroci, Marta,Vecchio, Stefano
-
supporting information; experimental part
p. 2251 - 2255
(2012/09/08)
-
- Synthesis of novel trisubstituted imidazolines
-
Imidazolines substituted at the 1- and either the 4-, or 5-position with phenyl and at the 2-position with alkyl or phenyl have been prepared in racemic form. They appear to be fairly stable compounds and potentially useful as scaffolds in medicinal chemistry. Georg Thieme Verlag Stuttgart.
- Lakner, Frederick J.,Parker, Matthew A.,Rogovoy, Boris,Khvat, Alexander,Ivachtchenko, Alexander
-
experimental part
p. 1987 - 1990
(2009/12/25)
-
- Convenient, cost-effective, and mild method for the N-acetylation of anilines and secondary amines
-
An efficient, cost-effective, and mild method for the N-acetylation of anilines and secondary amines with ammonium acetate in acetic acid media at reflux temperature in good yield is described. Copyright Taylor & Francis, Inc.
- Prasad,Srinivasa,Channe Gowda
-
p. 1189 - 1195
(2007/10/03)
-
- Thermolytic Carbonates for Potential 5′-Hydroxyl Protection of Deoxyribonucleosides
-
Thermolytic groups structurally related to well-studied heat-sensitive phosphate/thiophosphate protecting groups have been evaluated for 5′-hydroxyl protection of deoxyribonucleosides as carbonates and for potential use in solid-phase oligonucleotide synthesis. The spatial arrangement of selected functional groups forming an asymmetric nucleosidic 5′-O-carbonic acid ester has been designed to enable heat-induced cyclodecarbonation reactions, which would result in the release of carbon dioxide and the generation of a nucleosidic 5′-hydroxyl group. The nucleosidic 5′-O-carbonates 3-8, 10-15, and 19-21 were prepared and were isolated in yields ranging from 45 to 83%. Thermolytic deprotection of these carbonates is preferably performed in aqueous organic solvent at 90 °C under near neutral conditions. The rates of carbonate deprotection are dependent on the nucleophilicity of the functional group involved in the postulated cyclodecarbonation reaction and on solvent polarity. Deprotection kinetics increase according to the following order: 4 5 10 6 12 7 13 8 14 ? 19-21 and CC14 dioxane MeCN t-BuOH MeCN:phosphate buffer (3:1 v/v, pH 7.0) EtOH:phosphate buffer (1:1 v/v, pH 7.0). Complete thermolytic deprotection of carbonates 7, 8, 13, and 14 is achieved within 20 min to 2 h under optimal conditions in phosphate buffer-MeCN. The 2-(2-pyridyl)amino-1-phenylethyl and 2-[N-methyl-N-(2-pyridyl)]aminoethyl groups are particularly promising for 5′-hydroxyl protection of deoxyribonucleosides as thermolytic carbonates.
- Chmielewski, Marcin K.,Marchan, Vicente,Cieslak, Jacek,Grajkowski, Andrzej,Livengood, Victor,Muench, Ursula,Wilk, Andrzej,Beaucage, Serge L.
-
p. 10003 - 10012
(2007/10/03)
-
- Elevation of HDL cholesterol by N-[2-[(aminothioxomethyl) hydrazono]-2-arylethyl]amides
-
This invention relates to the treatment of atherosclerosis via raising the level of HDL cholesterol by administration of a compound of the formula STR1 wherein: R1, R2, and R3 are independently hydrogen, C1 -C6 alkyl or --(CH2)0-6 Ph where Ph is phenyl op
- -
-
-
- Horse liver esterase catalyzed enantioselective hydrolysis of N,O- diacetyl-2-amino-1-arylethanol
-
N,O-Diacetyl-2-amino-1-arylethanol can be efficiently resolved by horse liver esterase (HLE). A remarkable organic co-solvent effect on the enantioselectivity of HLE was observed.
- Laib, Taoues,Ouazzani, Jamal,Zhu, Jieping
-
p. 169 - 178
(2007/10/03)
-
- Investigations of Novel Azomethine Ylide-Forming Photoreactions of N-Silylmethylimides
-
The scope of a recently discovered (Yoon, E.C. et al.J.Am.Chem.Soc. 1995, 117, 2698), azomethine ylide-forming photoreaction has been explored by probing the excited state chemistry of several N-trimethylsilylmethyl substituted cyclic and acyclic imides and amide analogs.Photolysis of N-maleimide (4) in acetonitrile leads to efficient production of the tricyclic product 16, formed by trapping of the photogenerated azomethine ylide intermediate 15 through cycloaddition with 4.Irradiation 4 in solutions containing high concentrations of the dipolarophiles, acrylonitrile or fumaronitrile, results in production of the products (19-21 and 23-24, respectively) arising by cycloaddition of the ylide 15 with the added dipolarophiles.In contrast, photolysis of the nonconjugated cyclic imide, N-succinimide (5), brings about N-acyl migration resulting in the exclusive production of the unstable, iminolactone 30.On the other band, acyclic, N-trimethylsilylmethyl aroyl imides 6-8 undergo the excited state C to O silyl migration reaction to produce azomethine ylide intermediates 35.Both in the presence or absence of added dipolarophiles, these ylides undergo electrocyclization to form transient aziridine intermediates 36 which react further by ring opening to generate N-phenacylamide products 32-34.In contrast, the nonconjugated imide, N--N-acetylacetamide (9), is unreactive upon irradiation.Similarly, simple N-amides 10-13, while being photochemically labile, do not react to form "trappable" ylide intermediates upon irradiation.The results outlined above are presented and discussed in terms of the scope and limitations of the new, azomethine ylide-forming photoreaction of silylmethyl imides.
- Yoon, Ung Chan,Cho, Sung Ju,Lee, Yean-Jang,Mancheno, Maria J.,Mariano, Patrick S.
-
p. 2353 - 2360
(2007/10/02)
-
- Baker's Yeast Reduction of α-(Acylamino)acetophenones and Lipase Catalyzed Resolution of 2-Acylamino-1-arylethanols
-
Enzymatic reduction of α-acylaminoacetophenones with fermenting baker's yeast afforded optically active (R)-2-acylamino-1-arylethanols.Furthermore, lipase-catalyzed resolution of the 2-acylamino-1-arylethanols using vinyl acetate as an acyl donor resulted in the formation of (S)-1-acetoxy-2-acylamino-1-arylethanols and (R)-2-acylamino-1-arylethanols.
- Izumi, Taeko,Fukaya, Katsumi
-
p. 1216 - 1221
(2007/10/02)
-
- N-METHOXYDIACETAMIDE: A NEW SELECTIVE ACETYLATING AGENT
-
A simple and efficient method for the direct chemoselective acetylation of primary amines in the presence of alcohols or secondary amines using a new reagent N-methoxydiacetamide is described.
- Kikugawa, Yasuo,Mitsui, Kimiyo,Sakamoto, Takeshi,Kawase, Masami,Tamiya, Hiroshi
-
p. 243 - 246
(2007/10/02)
-
- Total Synthesis of (+/-) Resedine and (+/-)Resedinine Alkaloids from Reseda luteola
-
Total synthesis of racemic alkaloids: resedine and resedinine is described.
- Mieczkowski, Jozef B.
-
p. 109 - 113
(2007/10/02)
-