- Simple methodology for the preparation of amino alcohols from amino acid esters using nabh4-methanol in THF
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Amino alcohols constitute a very useful and versatile class of organic compounds, with important applications in synthetic and medicinal chemistry. However, in most of the procedures described in the literature for the obtainment of these compounds, considerable limitations can be found, such as drastic conditions, long time reactions, poor yields, and purification problems. The present article describes a methodology that gives amino alcohols and N-protected amino alcohols based on the reduction of amino acid esters under mild conditions, employing NaBH4 in the presence of methanol. The reactions occurred in a short time (15-20min) and provide yields of 50-95%.
- Goncalves,Pinheiro,Da Silva,Da Costa,Kaiser,De Souza
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- New solid-supported reagents (SSRs) for selective acylation of amines
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The pyrimidine linker (4) was prepared by solid phase synthesis starting from Merrifield resin. Acylation of 4 with different acyl chlorides gave polymer-bound 4-acyloxypyrimidines (2a-c), which proved to be useful solid-supported reagents for the selecti
- Botta, Maurizio,Corelli, Federico,Petricci, Elena,Seri, Catia
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- An improved synthesis of solid-supported reagents (SSRs) for selective acylation of amines by microwave irradiation
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Microwave-assisted acylation of a solid-supported pyrimidine linker with different acyl chlorides gave polymer-bound 4-acyloxypyrimidines, which in turn were used as SSRs for rapid and selective acylation of amines under microwave irradiation.
- Petricci, Elena,Botta, Maurizio,Corelli, Federico,Mugnaini, Claudia
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- N-acylcarbazole as a selective transamidation reagent
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N-acylation reaction offers an opportunity to develop an efficient synthesis of amide group-containing molecules. We found that N-acyl carbazoles showed remarkable selectivity in transamidation. Sterically less hindered primary amines are selectively acylated with N-acyl carbazoles without any additives. Various functional groups such as alcohol, phenol, indole, and aniline moieties are tolerated under mild conditions. The synthetic utility was displayed in one-pot synthesis of an N-acyl polyamine natural product. The terminal amines of spermidine were selectively benzoylated with N-benzoyl carbazole, followed by acetylation reaction accomplished the total synthesis in a highly efficient manner.
- Kang, Bubwoong,Kuse, Masaki,Okamura, Hironori,Sakai, Asumi,Satoh, Tetsuya,Shinada, Tetsuro,Yasuno, Yoko
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p. 993 - 999
(2020/09/22)
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- Chemoselective Synthesis of α-Amino-α-cyanophosphonates by Reductive Gem-Cyanation-Phosphonylation of Secondary Amides
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A novel approach to α-amino-α-cyanophosphonates has been developed. The method features a Tf2O-mediated reductive geminal cyanation/phosphonylation of secondary amides. Mild reaction conditions, high bond-forming efficiency, inexpensive readily available starting materials, and good to excellent yields with wide functional group compatibility constitute the main advantages of this method. The protocol can be run on a gram scale.
- Chen, Ting-Ting,Wang, Ai-E,Huang, Pei-Qiang
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supporting information
p. 3808 - 3812
(2019/05/24)
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- Microwave-Assisted Synthesis of 2-Aryl-2-oxazolines, 5,6-Dihydro-4H-1,3-oxazines, and 4,5,6,7-Tetrahydro-1,3-oxazepines
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The first general procedure for the synthesis of 5- to 7-membered cyclic iminoethers by microwave-assisted cyclization of ω-amido alcohols promoted by polyphosphoric acid (PPA) esters is presented. 2-Aryl-2-oxazolines and 5,6-dihydro-4H-1,3-oxazines were efficiently prepared using ethyl polyphosphate/CHCl3. Trimethylsilyl polyphosphate in solvent-free conditions allowed for the synthesis of hitherto-unreported 4,5,6,7-tetrahydro-1,3-oxazepines. The method involves good to excellent yields and short reaction times.The reaction mechanism and the role of PPA esters were investigated in a chiral substrate.
- Mollo, María C.,Orelli, Liliana R.
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supporting information
p. 6116 - 6119
(2016/12/09)
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- Targeting dopamine D3 and serotonin 5-HT1A and 5-HT2A receptors for developing effective antipsychotics: Synthesis, biological characterization, and behavioral studies
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Combination of dopamine D3 antagonism, serotonin 5-HT1A partial agonism, and antagonism at 5-HT2A leads to a novel approach to potent atypical antipsychotics. Exploitation of the original structure-activity relationships resulted in the identification of safe and effective antipsychotics devoid of extrapyramidal symptoms liability, sedation, and catalepsy. The potential atypical antipsychotic 5bb was selected for further pharmacological investigation. The distribution of c-fos positive cells in the ventral striatum confirmed the atypical antipsychotic profile of 5bb in agreement with behavioral rodent studies. 5bb administered orally demonstrated a biphasic effect on the MK801-induced hyperactivity at dose levels not able to induce sedation, catalepsy, or learning impairment in passive avoidance. In microdialysis studies, 5bb increased the dopamine efflux in the medial prefrontal cortex. Thus, 5bb represents a valuable lead for the development of atypical antipsychotics endowed with a unique pharmacological profile for addressing negative symptoms and cognitive deficits in schizophrenia.
- Brindisi, Margherita,Butini, Stefania,Franceschini, Silvia,Brogi, Simone,Trotta, Francesco,Ros, Sindu,Cagnotto, Alfredo,Salmona, Mario,Casagni, Alice,Andreassi, Marco,Saponara, Simona,Gorelli, Beatrice,Weikop, Pia,Mikkelsen, Jens D.,Scheel-Kruger, Jorgen,Sandager-Nielsen, Karin,Novellino, Ettore,Campiani, Giuseppe,Gemma, Sandra
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p. 9578 - 9597
(2015/01/09)
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- Laccase/2,2,6,6-tetramethylpiperidinoxyl radical (TEMPO): An efficient catalytic system for selective oxidations of primary hydroxy and amino groups in aqueous and biphasic media
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Copper salts/2,2,6,6-tetramethylpiperidinoxyl radical (TEMPO) catalytic systems enable efficient aerobic oxidations of primary alcohols but they generally show a reduced reactivity in aqueous medium. Herein, we report an oxidative catalytic system composed of Trametes versicolor laccase and TEMPO, which is able to work in buffer solutions at room temperature using ambient air. Although this catalytic system displays great efficiency in aqueous systems, the addition of methyl tert-butyl ether allows the reduction of TEMPO loading, also enhancing the solubility of hydrophobic compounds. This practical methodology promotes the chemoselective aerobic oxidation of hydroxy or amino groups, leading to interesting organic derivatives such as aldehydes, lactones, hemiaminals or lactams.
- Díaz-Rodríguez, Alba,Martínez-Montero, Lía,Lavandera, Iván,Gotor, Vicente,Gotor-Fernández, Vicente
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supporting information
p. 2321 - 2329
(2014/07/21)
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- Synthesis of 2-oxazolines and related N-containing heterocycles using [Et2NSF2]BF4 as a cyclodehydration agent
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The preparation of 2-oxazolines and related N-containing heterocycles from the corresponding hydroxyamides using XtalFluor-E ([Et2NSF 2s]BF4) as a cyclodehydration agent is described. A wide range of heterocycles are obtai
- Pouliot, Marie-France,Angers, Laetitia,Hamel, Jean-Denys,Paquin, Jean-Fran?ois
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supporting information; experimental part
p. 4121 - 4123
(2012/08/28)
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- The use of phosphonium anhydrides for the synthesis of 2-oxazolines, 2-thiazolines and 2-dihydrooxazine under mild conditions
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β-Hydroxy amides 6 and 7 were treated with triphenylphosphonium anhydride trifluoromethane sulfonate (3), or the cyclic analogue 4, to generate 2-oxazolines 5 and 8 under mild conditions. The reaction was optimised by examining the number of equivalents of reagents 3 or 4, or diisopropylethyl amine required to best effect cyclisation. The effects of altering the reaction temperature, reaction time, concentration, solvent, and addition rate also were investigated. However, it was found that use of a trityl group to block reaction at the hydroxyl or thiol group of the starting amides, and subsequent in situ detritylation, in the absence of base, led to greatly improved yields. Reagent 4 offered significant advantages in the purification of products and was used to dehydrate a range of trityl derivatives to form simple oxazolines, thiazolines, and a dihydro-1,3-oxazine, in high yield (85-99%), as well as a tetrahydro-1,3-oxazepine (31%).
- Petersson, Maria J.,Jenkins, Ian D.,Loughlin, Wendy A.
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supporting information; experimental part
p. 739 - 746
(2009/06/20)
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- MEDICAMENTS
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A compound of formula (I) is described: wherein R1 and R2 are as defined in the text and wherein the compounds are intended for use in treating medical conditions characterized by an imbalance in dopamine receptor activity.
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Page/Page column 61
(2009/06/27)
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- MEDICAMENTS
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A compound of the following formula is described (I), wherein X, Y, R1 and R are as defined in the text and wherein the compounds are intended for use in treating medical conditions characterized by an imbalance in dopamine receptor activity.
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Page/Page column 50
(2009/06/27)
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- Microwave-assisted acylation of amines, alcohols, and phenols by the use of Solid-Supported Reagents (SSRs)
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A microwave-assisted synthesis of solid-supported reagents for the acylation of amines has been developed, and the same methodology has been successfully applied to the preparation of acylating agents anchored on different solid supports. Similarly, alcohols, phenols, and thiophenols have been easily acylated using these reagents under microwave irradiation.
- Petricci, Elena,Mugnaini, Claudia,Radi, Marco,Corelli, Federico,Botta, Maurizio
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p. 7880 - 7887
(2007/10/03)
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- Synthesis of oxazines and thiazines by cyclodehydration of hydroxy amides and thioamides
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Dihydro-1,3-oxazines and -thiazines were obtained by cyclodehydration of hydroxy amides and thioamides with PEG-linked Burgess reagent or under Mitsunobu conditions. Yields were generally higher with polymer-Burgess reagent, but both conditions failed to
- Wipf, Peter,Hayes, Gregory B.
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p. 6987 - 6998
(2007/10/03)
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- Research on antiviral agents. 4. Studies on the chemistry of 6-methyl-2-methoxy-4-O-acyloxy and 6-methyl-2,4-di-O-acyloxypyrimidine derivatives as new acylation reagents and inhibitors of uracil DNA glycosylases.
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The synthesis of 6-methyl-2-methoxy-4-O-acyloxy and 6-methyl-2,4-di-O-acyloxypyrimidine derivatives 2 and 5 along with their properties as acylating agents of amines, alcohols, thiols and α-amino acids have been reported. Interestingly some of the title products revealed an inhibitory activity against the human and herpetic DNA glycosylases.
- Botta,Saladino,Gentile,Summa,Nicoletti,Verri,Focher,Spadari
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p. 3603 - 3618
(2007/10/02)
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- Hydroxylations microbiologiques de pyrrolidinones-2 (note de laboratoire)
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Microbial hydroxylations of various pyrrolidin-2 ones, especially N-acylated, with Beauveria sulfurescens have been carried out.The regioselectivity depends on the nature of the substituent on the nitrogen atom and the hydroxylation may occur at position 3,4 or 5 of the heterocycle.Hydroxylations at position 3 or 4 occur with low enantioselectivity.
- Srairi, Driss,Maurey, Georges
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p. 297 - 301
(2007/10/02)
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- Transformations microbiologiques, 5. Hydroxylation microbiologique de lactames, d'amides et d'imides monocycliques par le champignon Beauveria sulfurescens
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In this paper, we describe and comment on the results of the biohydroxylation of five, six and seven membered lactams, amides and imides by the fungus Beauveria sulfurescens.Analysis of the experimental results indicates that two distinct processes do presumably occur : i: Hydroxylation at position α to the nitrogen atom and, ii : hydroxylation of non activated carbon atoms.The first process would only occur when the second one is disfavoured for geometric reasons.The influence of the experimental conditions on the regioselectivity and on the reaction yields has been examined.The products obtained are generally not optically active.
- Archelas, Alain,Furstoss, Roland,Srairi, Driss,Maury, Georges
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p. 234 - 238
(2007/10/02)
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