scholarly journals A De Novo Synthetic Route to 1,2,3,4-Tetrahydroisoquinoline Derivatives

Synlett ◽  
2018 ◽  
Vol 29 (15) ◽  
pp. 2066-2070 ◽  
Author(s):  
Ferenc Fülöp ◽  
Loránd Kiss ◽  
Renáta Ábrahámi ◽  
Santos Fustero
Keyword(s):  
Ring Opening ◽  
Reductive Amination ◽  
De Novo ◽  
Synthetic Approach ◽  
Synthetic Route ◽  
Synthetic Strategy

A novel synthetic approach was developed for the construction of the 1,2,3,4-tetrahydroisoquinoline framework possessing varied functions. The synthetic strategy was based on oxidative ring opening of some indene derivatives through their C=C bond, followed by double reductive amination of the dicarbonyl intermediates with various primary alkyl- or fluoroalkylamines.

scholarly journals 2,3-Diaminopropanols Obtained from d-Serine as Intermediates in the Synthesis of Protected 2,3-l-Diaminopropanoic Acid (l-Dap) Methyl Esters

Molecules ◽  
2020 ◽  
Vol 25 (6) ◽  
pp. 1313
Author(s):  
Andrea Temperini ◽  
Donatella Aiello ◽  
Fabio Mazzotti ◽  
Constantinos M. Athanassopoulos ◽  
Pierantonio De Luca ◽  
...  
Keyword(s):  
Amino Acid ◽  
Reductive Amination ◽  
Methyl Esters ◽  
Primary Amines ◽  
Synthetic Approach ◽  
Protecting Group ◽  
Synthetic Strategy ◽  
Crude Product ◽  
Diaminopropanoic Acid ◽  
Acid Labile

A synthetic strategy for the preparation of two orthogonally protected methyl esters of the non-proteinogenic amino acid 2,3-l-diaminopropanoic acid (l-Dap) was developed. In these structures, the base-labile protecting group 9-fluorenylmethyloxycarbonyl (Fmoc) was paired to the p-toluensulfonyl (tosyl, Ts) or acid-labile tert-butyloxycarbonyl (Boc) moieties. The synthetic approach to protected l-Dap methyl esters uses appropriately masked 2,3-diaminopropanols, which are obtained via reductive amination of an aldehyde prepared from the commercial amino acid Nα-Fmoc-O-tert-butyl-d-serine, used as the starting material. Reductive amination is carried out with primary amines and sulfonamides, and the process is assisted by the Lewis acid Ti(OiPr)4. The required carboxyl group is installed by oxidizing the alcoholic function of 2,3-diaminopropanols bearing the tosyl or benzyl protecting group on the 3-NH2 site. The procedure can easily be applied using the crude product obtained after each step, minimizing the need for chromatographic purifications. Chirality of the carbon atom of the starting d-serine template is preserved throughout all synthetic steps.

scholarly journals A Convenient Synthesis of (16S,20S)-3β-Hydroxy-5α-pregnane-20,16-carbolactam and Its N-alkyl Derivatives

Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2377
Author(s):  
Agnieszka Wojtkielewicz ◽  
Damian Pawelski ◽  
Przemysław Bazydło ◽  
Aneta Baj ◽  
Stanisław Witkowski ◽  
...  
Keyword(s):  
Ring Opening ◽  
Reductive Amination ◽  
Lactone Ring ◽  
Synthetic Route ◽  
Microwave Assisted ◽  
Alkyl Derivatives ◽  
Convenient Synthesis

A concise synthesis of (16S,20S)-3β-hydroxy-5α-pregnane-20,16-carbolactam from tigogenin via the corresponding lactone is described. The most efficient synthetic route consisted of the lactone ring-opening with aminoalane reagent followed by PDC or Dess-Martin oxidation. The oxo-amide obtained was subjected to cyclization with Et3SiH/TFA or Et3SiH/Bi(TfO)3. Alternately, the lactone was converted first to the oxo-acid, which was then subjected to the microwave-assisted reductive amination. N-Alkyl derivatives were also obtained in a similar way.

Regioselective Dye-Induced Photocleavage of Epoxides as an Alternative Mild Synthetic Route to a Targeted Alcohol Functionality

2015 ◽  
Vol 68 (3) ◽  
pp. 500 ◽  
Author(s):  
Anthony A. Provatas ◽  
Gary A. Epling ◽  
James D. Stuart ◽  
Aliaksandr Yeudakimau
Keyword(s):  
Electron Transfer ◽  
Visible Light ◽  
Ring Opening ◽  
Radical Anion ◽  
Transfer Reaction ◽  
Electron Transfer Reaction ◽  
Hydroxyl Group ◽  
Synthetic Approach ◽  
Synthetic Route ◽  
Toxic Dyes

The regioselective cleavage of epoxides using visible light and a catalytic dye is reported in this study as an alternative mild synthetic approach. The epoxide radical anion is generated via visible light in an electron transfer reaction, induced by non-toxic dyes, leading to ring opening and formation of the corresponding alcohol with the hydroxyl group on the less substituted carbon in excellent yields.

A Metathetic Approach to [5/5/6] Aza-Tricyclic Core of Dendrobine, Kopsanone, and Lycopalhine A Type of Alkaloids

Synthesis ◽  
2019 ◽  
Vol 51 (21) ◽  
pp. 3981-3988 ◽  
Author(s):  
Sambasivarao Kotha ◽  
Sunil Pulletikurti
Keyword(s):  
Lewis Acid ◽  
Ring Opening ◽  
Synthetic Approach ◽  
Synthetic Route ◽  
Ring Closing Metathesis ◽  
Tricyclic Core

A concise synthetic approach to [5/5/6] tricyclic pyrrolidine core of dendrobine is reported. This methodology relies on the construction of β-hydroxylactams by NaBH4-I2 reduction followed by reaction of allylsilane with the aid of Lewis acid to generate alkenyl lactams in good yields. Further, ring-opening metathesis (ROM) followed by ring-closing metathesis (RCM) were used to assemble the [5/5/6] aza-tricyclic skeleton of dendrobine. This short synthetic route has been expanded to assemble tricyclic [5/5/8] system with pentenylboronic acid.

Antipsychotic drug Cariprazine synthesis: An improved and commercially viable synthetic approach

2021 ◽  
Vol 18 ◽  
Author(s):  
Adilakshmi Singavarapu ◽  
Gowri Sankar Reddipalli ◽  
Venkat Reddy Ghojala
Keyword(s):  
Antipsychotic Drug ◽  
Reductive Amination ◽  
Synthetic Approach ◽  
The Novel ◽  
Synthetic Route ◽  
Reaction Conditions ◽  
Weinreb Amide ◽  
Commercial Scale ◽  
Hydrolysis Of

: The novel synthetic route to an antipsychotic drug Cariprazine was developed and demonstrated on a commercial scale. The synthesis of Cariprazine is achieved from N-(4-oxocyclohexyl) acetamide by using various reactions such as Wittig-Horner reaction, reduction of alkene, hydrolysis of ester, deacylation, amidation, reduction of weinreb amide to yield the corresponding aldehyde, and finally reductive amination of aldehyde in presence of the corresponding amine to form Cariprazine. In this article, we report a novel intermediate 2-[trans-4-(3,3-Dimethylureido)cyclohexyl]-N-methoxy-N-methylacetamide by avoiding potentially genotoxic substances/intermediates, tedious, drastic reaction conditions.

scholarly journals Synthesis of 3,3-Diaryl/Heteroarylpropylamines via Nucleophilic Ring Opening of Activated Azetidines with Arenes and Heteroarenes: New Synthetic Route to (±)Tolterodine

ACS Omega ◽  
2018 ◽  
Vol 3 (12) ◽  
pp. 17562-17572 ◽  
Author(s):  
Gaurav Goswami ◽  
Navya Chauhan ◽  
Abhijit Mal ◽  
Subhomoy Das ◽  
Mowpriya Das ◽  
...  
Keyword(s):  
Ring Opening ◽  
Synthetic Route ◽  
Nucleophilic Ring Opening

scholarly journals General synthetic strategy for regioselective ultrafast formation of disulfide bonds in peptides and proteins

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shay Laps ◽  
Fatima Atamleh ◽  
Guy Kamnesky ◽  
Hao Sun ◽  
Ashraf Brik
Keyword(s):  
Drug Discovery ◽  
Disulfide Bonds ◽  
Unsolved Problem ◽  
De Novo ◽  
Therapeutic Potential ◽  
Selective Activation ◽  
One Pot ◽  
Synthetic Strategy ◽  
The One ◽  
Game Changer

AbstractDespite six decades of efforts to synthesize peptides and proteins bearing multiple disulfide bonds, this synthetic challenge remains an unsolved problem in most targets (e.g., knotted mini proteins). Here we show a de novo general synthetic strategy for the ultrafast, high-yielding formation of two and three disulfide bonds in peptides and proteins. We develop an approach based on the combination of a small molecule, ultraviolet-light, and palladium for chemo- and regio-selective activation of cysteine, which enables the one-pot formation of multiple disulfide bonds in various peptides and proteins. We prepare bioactive targets of high therapeutic potential, including conotoxin, RANTES, EETI-II, and plectasin peptides and the linaclotide drug. We anticipate that this strategy will be a game-changer in preparing millions of inaccessible targets for drug discovery.

A simple synthetic route to polyoxovanadate-based organic–inorganic hybrids using EEDQ as an ester coupling agent

2017 ◽  
Vol 46 (14) ◽  
pp. 4602-4608 ◽  
Author(s):  
Aruuhan Bayaguud ◽  
JianDa Li ◽  
Shan She ◽  
Yongge Wei
Keyword(s):  
Coupling Agent ◽  
Synthetic Route ◽  
Synthetic Strategy ◽  
Post Functionalization

A simple synthetic strategy for the post-functionalization of organically derivatized hexavanadates is presented.

scholarly journals Microwave Heating Promotes the S-Alkylation of Aziridine Catalyzed by Molecular Sieves: A Post-Synthetic Approach to Lanthionine-Containing Peptides

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6135
Author(s):  
Valentina Verdoliva ◽  
Giuseppe Digilio ◽  
Michele Saviano ◽  
Stefania De Luca
Keyword(s):  
Microwave Irradiation ◽  
Molecular Sieves ◽  
Ring Opening ◽  
Cysteine Residue ◽  
Biologically Active ◽  
Synthetic Approach ◽  
Stepwise Approach ◽  
Valuable Alternative ◽  
Ring Opening Reactions ◽  
Nucleophilic Ring Opening

Aziridine derivatives involved in nucleophilic ring-opening reactions have attracted great interest, since they allow the preparation of biologically active molecules. A chemoselective and mild procedure to convert a peptide cysteine residue into lanthionine via S-alkylation on aziridine substrates is presented in this paper. The procedure relies on a post-synthetic protocol promoted by molecular sieves to prepare lanthionine-containing peptides and is assisted by microwave irradiation. In addition, it represents a valuable alternative to the stepwise approach, in which the lanthionine precursor is incorporated into peptides as a building block.

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