scholarly journals Taming Combinatorial Explosion of the Formose Reaction via Recursion within Mineral Environments

2019 ◽  
Author(s):  
Leroy Cronin ◽  
Stephanie Colón-Santos ◽  
Geoffrey Cooper
Keyword(s):  
Building Blocks ◽  
Complex Mixtures ◽  
Mineral Surfaces ◽  
One Pot ◽  
Combinatorial Explosion ◽  
Formose Reaction ◽  
Product Mixture ◽  
Number Of Cycles ◽  
Reaction Cycles

<p><i>One-pot reactions of simple precursors, such as those found in the formose reaction or formamide condensation, continuously lead to combinatorial explosions in which simple building blocks capable of function exist, but are in insufficient concentration to self-organize, adapt, and thus generate complexity. We set out to explore the effect of recursion on such complex mixtures by ‘seeding’ the product mixture into a fresh version of the reaction, with the inclusion of different mineral environments, over a number of reaction cycles. Through untargeted UPLC-HRMS analysis of the mixtures<a> we found that the overall number of products detected reduces as the number of cycles increases, as a result of recursively enhanced mineral environment selectivity, </a>thus limiting the combinatorial explosion. This discovery demonstrates how the involvement of mineral surfaces with simple reactions could lead to the emergence of some building blocks found in RNA, </i><i>Ribose and Uracil, under much simpler conditions that originally thought.</i><i> </i></p>

scholarly journals Taming Combinatorial Explosion of the Formose Reaction via Recursion within Mineral Environments

2019 ◽  
Author(s):  
Leroy Cronin ◽  
Stephanie Colón-Santos ◽  
Geoffrey Cooper
Keyword(s):  
Building Blocks ◽  
Complex Mixtures ◽  
Mineral Surfaces ◽  
One Pot ◽  
Combinatorial Explosion ◽  
Formose Reaction ◽  
Product Mixture ◽  
Number Of Cycles ◽  
Reaction Cycles

<p><i>One-pot reactions of simple precursors, such as those found in the formose reaction or formamide condensation, continuously lead to combinatorial explosions in which simple building blocks capable of function exist, but are in insufficient concentration to self-organize, adapt, and thus generate complexity. We set out to explore the effect of recursion on such complex mixtures by ‘seeding’ the product mixture into a fresh version of the reaction, with the inclusion of different mineral environments, over a number of reaction cycles. Through untargeted UPLC-HRMS analysis of the mixtures<a> we found that the overall number of products detected reduces as the number of cycles increases, as a result of recursively enhanced mineral environment selectivity, </a>thus limiting the combinatorial explosion. This discovery demonstrates how the involvement of mineral surfaces with simple reactions could lead to the emergence of some building blocks found in RNA, </i><i>Ribose and Uracil, under much simpler conditions that originally thought.</i><i> </i></p>

Synthesis of Nitrile-Bearing Quaternary Centers via an Equilibrium-Driven Transnitrilation and Anion-Relay Strategy

2019 ◽  
Author(s):  
Sebastien Alazet ◽  
Michael West ◽  
Purvish Patel ◽  
Sophie Rousseaux
Keyword(s):  
Building Blocks ◽  
One Pot ◽  
Quaternary Centers ◽  
Synthetic Intermediates

The efficient preparation of nitrile-containing building blocks is of interest due to their utility as synthetic intermediates and their prevalence in pharmaceuticals. As a result, significant efforts have been made to develop methods to access these motifs which rely on safer and non-toxic sources of CN. Herein, we report that 2-methyl-2-phenylpropanenitrile is an efficient, non-toxic, electrophilic CN source for the synthesis of nitrile-bearing quaternary centers via a thermodynamic transnitrilation and anion-relay strategy. This one-pot process leads to nitrile products resulting from the gem-difunctionalization of alkyl lithium reagents.<br>

scholarly journals 2-Aryl-6-Polyfluoroalkyl-4-Pyrones as Promising RF-Building-Blocks: Synthesis and Application for Construction of Fluorinated Azaheterocycles

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4415
Author(s):  
Sergey A. Usachev ◽  
Diana I. Nigamatova ◽  
Daria K. Mysik ◽  
Nikita A. Naumov ◽  
Dmitrii L. Obydennov ◽  
...  
Keyword(s):  
Direct Synthesis ◽  
Building Blocks ◽  
Oxidative Cyclization ◽  
One Pot ◽  
Synthetic Application ◽  
General Method

A convenient and general method for the direct synthesis of 2-aryl-6-(trifluoromethyl)-4-pyrones and 2-aryl-5-bromo-6-(trifluoromethyl)-4-pyrones has been developed on the basis of one-pot oxidative cyclization of (E)-6-aryl-1,1,1-trifluorohex-5-ene-2,4-diones via a bromination/dehydrobromination approach. This strategy was also applied for the preparation of 2-phenyl-6-polyfluoroalkyl-4-pyrones and their 5-bromo derivatives. Conditions of chemoselective enediones bromination were found and the key intermediates of the cyclization of bromo-derivatives to 4-pyrones were characterized. Synthetic application of the prepared 4-pyrones has been demonstrated for the construction of biologically important CF3-bearing azaheterocycles, such as pyrazoles, pyridones, and triazoles.

scholarly journals 1,3-Diketone Calix[4]arene Derivatives—A New Type of Versatile Ligands for Metal Complexes and Nanoparticles

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1214
Author(s):  
Sergey N. Podyachev ◽  
Rustem R. Zairov ◽  
Asiya R. Mustafina
Keyword(s):  
Structural Diversity ◽  
Building Blocks ◽  
Structural Features ◽  
Structure Property ◽  
One Pot ◽  
Arene Ligands ◽  
Structure Property Relationships ◽  
New Type ◽  
Synthetic Routes ◽  
Magnetic Resonance Imaging Mri

The present review is aimed at highlighting outlooks for cyclophanic 1,3-diketones as a new type of versatile ligands and building blocks of the nanomaterial for sensing and bioimaging. Thus, the main synthetic routes for achieving the structural diversity of cyclophanic 1,3-diketones are discussed. The structural diversity is demonstrated by variation of both cyclophanic backbones (calix[4]arene, calix[4]resorcinarene and thiacalix[4]arene) and embedding of different substituents onto lower or upper macrocyclic rims. The structural features of the cyclophanic 1,3-diketones are correlated with their ability to form lanthanide complexes exhibiting both lanthanide-centered luminescence and magnetic relaxivity parameters convenient for contrast effect in magnetic resonance imaging (MRI). The revealed structure–property relationships and the applicability of facile one-pot transformation of the complexes to hydrophilic nanoparticles demonstrates the advantages of 1,3-diketone calix[4]arene ligands and their complexes in developing of nanomaterials for sensing and bioimaging.

Access to Unnatural Glycosyl Amino Acid Building Blocks via a One-Pot Ritter Reaction

Synlett ◽  
2005 ◽  
pp. 212-216 ◽  
Author(s):  
Frank Schweizer ◽  
Marlin Penner ◽  
David Taylor ◽  
Danielle Desautels ◽  
Kirk Marat
Keyword(s):  
Amino Acid ◽  
Building Blocks ◽  
Ritter Reaction ◽  
One Pot

Symmetrical tetra-β″-sulfoleno-meso-aryl-porphyrins — synthesis, spectroscopy and structural characterization

2014 ◽  
Vol 18 (01n02) ◽  
pp. 115-122 ◽  
Author(s):  
Srinivas Banala ◽  
Klaus Wurst ◽  
Bernhard Kräutler
Keyword(s):  
Metal Complexes ◽  
Crystal Structures ◽  
Structural Characterization ◽  
Building Blocks ◽  
Cycloaddition Reactions ◽  
One Pot

We report here the preparation (in "one-pot") of a tetra-β″-sulfoleno-meso-aryl-porphyrin in about 80% yield by using an optimized modification of Lindsey's variant of the Adler–Longo approach. The Zn ( II )-, Cu ( II )- and Ni ( II )-complexes of the symmetrical porphyrin were prepared and characterized spectroscopically. Crystal structures of the fluorescent Zn ( II )- and of the non-fluorescent Ni ( II )-tetra-β″-sulfoleno-meso-aryl-porphyrinates showed the highly substituted porphyrin ligands to be nearly perfectly planar. The Zn ( II )-complex of this porphyrin has been used as a thermal precursor of a reactive diene, and — formally — of lateral and diagonal bis-dienes, of a tris-diene and of a tetra-diene, which all underwent [4 + 2]-cycloaddition reactions in situ with a range of dienophiles. Thus, the tetra-β″-sulfoleno-meso-aryl-porphyrin and its metal complexes represent reactive building blocks, "programmed" for the syntheses of symmetrical and highly functionalized porphyrins.

scholarly journals Thioesters Provide a Robust Path to Prebiotic Peptides

2021 ◽  
Author(s):  
Moran Frenkel-Pinter ◽  
Marcos Bouza ◽  
Facundo M. Fernández ◽  
Luke J. Leman ◽  
Loren Dean Williams ◽  
...  
Keyword(s):  
Building Blocks ◽  
Peptide Bond ◽  
Side Reactions ◽  
Peptide Bond Formation ◽  
One Pot ◽  
Complex Molecules ◽  
Peptide Formation ◽  
Wide Range ◽  
Amide Exchange ◽  
Prebiotic Earth

The condensation of building blocks into oligomers and polymers was an early and important stage in the origins of life. High activation energies, unfavorable thermodynamics and side reactions are bottlenecks for abiotic formation of peptides. Thioesters are hypothesized to have played key roles in prebiotic chemistry on early Earth, serving as energy storing molecules, as synthetic intermediates, and as catalysts in the formation of more complex molecules, including polypeptides. However, all abiotic reactions reported thus far for peptide formation via thioester intermediates have relied on activated building blocks or condensing agents, which are of questionable prebiotic relevance. We report robust, plausible prebiotic reactions of mercaptoacids with amino acids that result in the formation of peptides and thiodepsipeptides, which contain both peptide and thioester bonds. Peptide bond formation proceeds by the condensation of mercaptoacids to form thioesters followed by thioester-amide exchange. Mercaptoacids catalyze thiodepsipeptides and peptide formation under a wide range of pH conditions and at mild temperatures. Our results offer the most robust one-pot pathway for peptide formation ever reported. These results support the hypothesis that thiodepsipeptides formed robustly on prebiotic Earth and were possible contributors to early chemical evolution.

Contribution to PNA-RNA Chimera Synthesis: One-Pot Microwave-Assisted Ugi Reaction to Obtain Dimeric Building Blocks

2016 ◽  
Vol 2017 (3) ◽  
pp. 469-475 ◽  
Author(s):  
Reuben Ovadia ◽  
Clémence Mondielli ◽  
Jean-Jacques Vasseur ◽  
Carine Baraguey ◽  
Karine Alvarez
Keyword(s):  
Building Blocks ◽  
Ugi Reaction ◽  
One Pot ◽  
Microwave Assisted

A Comprehensive One-Pot Synthesis of Protected Cysteine and Selenocysteine SPPS Derivatives

2014 ◽  
Vol 21 (12) ◽  
pp. 1257-1264
Author(s):  
Stevenson Flemer
Keyword(s):  
Solid Phase ◽  
Solid Phase Peptide Synthesis ◽  
Reduction Process ◽  
Building Blocks ◽  
High Yield ◽  
One Pot ◽  
Peptide Models ◽  
Direct Use ◽  
Proof Of Principle ◽  
Subsequent Incorporation

A proof-of-principle methodology is presented in which all commercially-available cysteine (Cys) and selenocysteine (Sec) solid phase peptide synthesis (SPPS) derivatives are synthesized in high yield from easily prepared protected dichalcogenide precursors. A Zn-mediated biphasic reduction process applied to a series of four bis-Nα-protected dichalcogenide compounds allows facile conversion to their corresponding thiol and selenol intermediates followed by insitu S- or Se-alkylation with various electrophiles to directly access twenty one known Cys and Sec SPPS derivatives. Most of these derivatives were able to be precipitated in crude form out of petroleum ether in sufficient purity for direct use as peptide building blocks. Subsequent incorporation of these derivatives into peptide models nicely illustrates their viability and applicability toward SPPS.

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