scholarly journals Bicatalytic Multistep Reactions En Route to the One-Pot Total Synthesis of Complex Molecules: Easy Access to Chromene and 1,2-Dihydroquinoline Derivatives from Simple Substrates

ChemCatChem ◽  
2016 ◽  
Vol 9 (1) ◽  
pp. 70-75 ◽  
Author(s):  
Pascal D. Giorgi ◽  
Peter J. Miedziak ◽  
Jennifer K. Edwards ◽  
Graham J. Hutchings ◽  
Sylvain Antoniotti
Keyword(s):  
Total Synthesis ◽  
Easy Access ◽  
One Pot ◽  
Complex Molecules ◽  
Multistep Reactions ◽  
The One

One-pot total synthesis of streptindole, arsindoline B and their congeners through tandem decarboxylative deaminative dual-coupling reaction of amino acids with indoles

2015 ◽  
Vol 13 (14) ◽  
pp. 4240-4247 ◽  
Author(s):  
Jiachen Xiang ◽  
Jungang Wang ◽  
Miao Wang ◽  
Xianggao Meng ◽  
Anxin Wu
Keyword(s):  
Amino Acids ◽  
Natural Products ◽  
Total Synthesis ◽  
Coupling Reaction ◽  
One Pot ◽  
The One

This paper described a decarboxylative deaminative dual-coupling reaction of amino acids with indoles to afford BIM scaffolds and its further application to the one-pot total synthesis of natural products.

scholarly journals Total synthesis of the O-antigen repeating unit of Providencia stuartii O49 serotype through linear and one-pot assemblies

2021 ◽  
Vol 17 ◽  
pp. 2915-2921
Author(s):  
Tanmoy Halder ◽  
Somnath Yadav
Keyword(s):  
Total Synthesis ◽  
Pathogenic Bacteria ◽  
Capsular Polysaccharides ◽  
One Pot ◽  
Antibiotic Resistant ◽  
O Antigen ◽  
The Family ◽  
Providencia Stuartii ◽  
The One ◽  
Tract Infections

Capsular polysaccharides of pathogenic bacteria have been reported to be effective vaccines against diseases caused by them. Providencia stuartii is a class of enterobacteria of the family Providencia that is responsible for several antibiotic resistant infections, particularly urinary tract infections of patients with prolonged catheterization in hospital settings. Towards the goal of development of vaccine candidates against this pathogen, we herein report the total synthesis of a trisaccharide repeating unit of the O-antigen polysaccharide of the P. stuartii O49 serotype containing the →6)-β-ᴅ-Galp-(1→3)-β-ᴅ-GalpNAc(1→4)-α-ᴅ-Galp(1→ linkage. The synthesis of the trisaccharide repeating unit was carried out first by a linear strategy involving the [1 + (1 + 1 = 2)] assembly, followed by a one-pot synthesis involving [1 + 1 + 1] strategy from the corresponding monosaccharides. The one-pot method provided a higher yield of the protected trisaccharide intermediate (73%) compared to the two step synthesis (66%). The protected trisaccharide was then deprotected and N-acetylated to finally afford the desired trisaccharide repeating unit as its α-p-methoxyphenyl glycoside.

scholarly journals Copper-mediated selenazolidine deprotection enables one-pot chemical synthesis of challenging proteins

2019 ◽  
Author(s):  
Zhenguang Zhao ◽  
Norman Metanis
Keyword(s):  
Protein Synthesis ◽  
Catalytic Activity ◽  
Chemical Synthesis ◽  
Total Synthesis ◽  
Active Site ◽  
Synthetic Approach ◽  
One Pot ◽  
Chemical Protein Synthesis ◽  
Key Technologies ◽  
The One

<p>While chemical protein synthesis (CPS) has granted access to challenging proteins, synthesis of longer proteins is often limited by low abundance or non-strategic placement of cysteine (Cys) residues, essential for native chemical ligations (NCL), as well as multiple purification and isolation steps. Selective deselenization and one-pot CPS serve as key technologies to circumvent these issues. Herein, we describe the one-pot total synthesis of human thiosulfate: glutathione sulfurtransferase (TSTD1), a 115-residue protein with a single Cys residue at its active site, and its seleno-analogue. WT-TSTD1 was synthesized in a C-to-N synthetic approach employing multiple NCL reactions, Cu(II)-mediated deprotection of selenazolidine (Sez), and chemoselective deselenization, all in one-pot. In addition, the protein’s seleno analogue (Se-TSTD1), in which the active site Cys is replaced with selenocysteine, was synthesized with a kinetically controlled ligation in a one-pot, N-to-C synthetic approach. TSTD1’s one-pot synthesis was made possible by the newly reported, rapid, and facile copper-mediated selenazolidine deprotection that can be accomplished in one minute. Finally, catalytic activity of the two proteins indicated that Se-TSTD1 possessed only four-fold lower activity than WT-TSTD1 as a thiosulfate: glutathione sulfurtransferase, suggesting that selenoproteins can have physiologically comparable sulfutransferase activity as their cysteine counterparts. </p>

scholarly journals A novel protocol for the one-pot borylation/Suzuki reaction provides easy access to hinge-binding groups for kinase inhibitors

2016 ◽  
Vol 14 (3) ◽  
pp. 963-969 ◽  
Author(s):  
A. Hooper ◽  
A. Zambon ◽  
C. J. Springer
Keyword(s):  
Kinase Inhibitors ◽  
Suzuki Reaction ◽  
Easy Access ◽  
One Pot ◽  
Microwave Assisted ◽  
The One ◽  
Microwave Assisted Method

This new microwave-assisted method provides a quick one-pot borylation/Suzuki protocol that does not require additional ligands nor double loading of catalyst.

scholarly journals Copper-mediated selenazolidine deprotection enables one-pot chemical synthesis of challenging proteins

2019 ◽  
Author(s):  
Zhenguang Zhao ◽  
Norman Metanis
Keyword(s):  
Protein Synthesis ◽  
Catalytic Activity ◽  
Chemical Synthesis ◽  
Total Synthesis ◽  
Active Site ◽  
Synthetic Approach ◽  
One Pot ◽  
Chemical Protein Synthesis ◽  
Key Technologies ◽  
The One

<p>While chemical protein synthesis (CPS) has granted access to challenging proteins, synthesis of longer proteins is often limited by low abundance or non-strategic placement of cysteine (Cys) residues, essential for native chemical ligations (NCL), as well as multiple purification and isolation steps. Selective deselenization and one-pot CPS serve as key technologies to circumvent these issues. Herein, we describe the one-pot total synthesis of human thiosulfate: glutathione sulfurtransferase (TSTD1), a 115-residue protein with a single Cys residue at its active site, and its seleno-analogue. WT-TSTD1 was synthesized in a C-to-N synthetic approach employing multiple NCL reactions, Cu(II)-mediated deprotection of selenazolidine (Sez), and chemoselective deselenization, all in one-pot. In addition, the protein’s seleno analogue (Se-TSTD1), in which the active site Cys is replaced with selenocysteine, was synthesized with a kinetically controlled ligation in a one-pot, N-to-C synthetic approach. TSTD1’s one-pot synthesis was made possible by the newly reported, rapid, and facile copper-mediated selenazolidine deprotection that can be accomplished in one minute. Finally, catalytic activity of the two proteins indicated that Se-TSTD1 possessed only four-fold lower activity than WT-TSTD1 as a thiosulfate: glutathione sulfurtransferase, suggesting that selenoproteins can have physiologically comparable sulfutransferase activity as their cysteine counterparts. </p>

Palladium-Catalyzed Synthesis of Diarylamines and 1- and 2-Oxygenated Carbazoles: Total Syntheses of Natural Alkaloids Clauraila A, Clausenal, Clausine P, and 7-Methoxy-O-methylmukonal

Synthesis ◽  
2017 ◽  
Vol 49 (18) ◽  
pp. 4357-4371 ◽  
Author(s):  
Joaquín Tamariz ◽  
R. Hernández-Benitez ◽  
Daniel Zárate-Zárate ◽  
Francisco Delgado
Keyword(s):  
Total Synthesis ◽  
One Pot ◽  
Total Syntheses ◽  
Naturally Occurring ◽  
Palladium Catalyzed ◽  
The One

The scope and limitations of the strategy for the conversion of 2-anilinocyclohexenones and N-arylcyclohexane enaminones into the 1- and 2-oxygenated carbazole scaffolds, respectively, were evaluated. The one-pot palladium(0)-catalyzed aromatization/methylation process of the aforementioned substrates provided a diversity of the corresponding diarylamines. A subsequent palladium(II)-catalyzed cyclization of the latter delivered the desired 1- and 2-oxygenated carbazoles in good overall yields. Special attention was given to the synthesis of the uncommon 1,8-disubstituted carbazoles. This methodology was employed for the total synthesis of the naturally occurring clauraila A, clausenal, clausine P, and 7-methoxy-O-methylmukonal.

Migration and US agricultural competitiveness

2013 ◽  
Vol 10 (2) ◽  
pp. 159-179 ◽  
Author(s):  
Philip L. Martin
Keyword(s):  
Farm Workers ◽  
Easy Access ◽  
Foreign Born ◽  
Guest Workers ◽  
Long Run ◽  
Short Run ◽  
Lower Wage ◽  
The Government ◽  
The One

Agriculture has one of the highest shares of foreign-born and unauthorized workers among US industries; over three-fourths of hired farm workers were born abroad, usually in Mexico, and over half of all farm workers are unauthorized. Farm employers are among the few to openly acknowledge their dependence on migrant and unauthorized workers, and they oppose efforts to reduce unauthorized migration unless the government legalizes currently illegal farm workers or provides easy access to legal guest workers. The effects of migrants on agricultural competitiveness are mixed. On the one hand, wages held down by migrants keep labour-intensive commodities competitive in the short run, but the fact that most labour-intensive commodities are shipped long distances means that long-run US competitiveness may be eroded as US farmers have fewer incentives to develop labour-saving and productivity-improving methods of farming and production in lower-wage countries expands.

Metal-, and Organocatalyst-Free One-Pot Assembly of Chiral Aza-Tricyclic Molecules: Creating Six Contiguous Stereocenters from 2-D-Structures and an Amino Acid

2020 ◽  
Author(s):  
Dung Do
Keyword(s):  
Amino Acid ◽  
Chemical Space ◽  
Structural Diversity ◽  
Therapeutic Agents ◽  
Chiral Molecules ◽  
One Pot ◽  
Complex Molecules ◽  
Chiral Catalyst ◽  
Chiral Complex ◽  
Free Process

<p>Chiral molecules with their defined 3-D structures are of paramount importance for the study of chemical biology and drug discovery. Having rich structural diversity and unique stereoisomerism, chiral molecules offer a large chemical space that can be explored for the design of new therapeutic agents.<sup>1</sup> Practically, chiral architectures are usually prepared from organometallic and organocatalytic processes where a transition metal or an organocatalyst is tailor-made for desired reactions. As a result, developing a method that enables rapid assembly of chiral complex molecules under metal- and organocatalyst-free condition represents a daunting challenge. Here we developed a straightforward route to create a chiral 3-D structure from 2-D structures and an amino acid without any chiral catalyst. The center of this research is the design of a <a>special chiral spiroimidazolidinone cyclohexadienone intermediate</a>, a merger of a chiral reactive substrate with multiple nucleophillic/electrophillic sites and a transient organocatalyst. <a>This unique substrate-catalyst (“subcatalyst”) dual role of the intermediate enhances </a><a>the coordinational proximity of the chiral substrate and catalyst</a> in the key Aza-Michael/Michael cascade resulting in a substantial steric discrimination and an excellent overall diastereoselectivity. Whereas the “subcatalyst” (hidden catalyst) is not present in the reaction’s initial components, which renders a chiral catalyst-free process, it is strategically produced to promote sequential self-catalyzed reactions. The success of this methodology will pave the way for many efficient preparations of chiral complex molecules and aid for the quest to create next generation of therapeutic agents.</p>

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