scholarly journals A Sustainable Improvement of ω-Bromoalkylphosphonates Synthesis to Access Novel KuQuinones

Organics ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 107-117
Author(s):  
Mattia Forchetta ◽  
Valeria Conte ◽  
Giulia Fiorani ◽  
Pierluca Galloni ◽  
Federica Sabuzi
Keyword(s):  
Metal Oxides ◽  
Phosphonic Acid ◽  
Organic Molecules ◽  
Building Blocks ◽  
Reaction Conditions ◽  
Phosphonic Acids ◽  
Sustainable Improvement ◽  
Phosphonate Esters ◽  
First Time ◽  
Complex Organic

Owing to the attractiveness of organic phosphonic acids and esters in the pharmacological field and in the functionalization of conductive metal-oxides, the research of effective synthetic protocols is pivotal. Among the others, ω-bromoalkylphosphonates are gaining particular attention because they are useful building blocks for the tailored functionalization of complex organic molecules. Hence, in this work, the optimization of Michaelis–Arbuzov reaction conditions for ω-bromoalkylphosphonates has been performed, to improve process sustainability while maintaining good yields. Synthesized ω-bromoalkylphosphonates have been successfully adopted for the synthesis of new KuQuinone phosphonate esters and, by hydrolysis, phosphonic acid KuQuinone derivatives have been obtained for the first time. Considering the high affinity with metal-oxides, KuQuinones bearing phosphonic acid terminal groups are promising candidates for biomedical and photo(electro)chemical applications.

scholarly journals Fullerenes in the IC 348 star cluster of the Perseus Molecular Cloud

2019 ◽  
Author(s):  
S Iglesias-Groth
Keyword(s):  
Molecular Cloud ◽  
Organic Molecules ◽  
Protoplanetary Disks ◽  
Building Blocks ◽  
Cluster Emission ◽  
Star Forming ◽  
Available Carbon ◽  
Prebiotic Molecules ◽  
Complex Organic ◽  
Early Phases

Abstract We present the detection of fullerenes C60 and C70 in the star-forming region IC 348 of the Perseus molecular cloud. Mid-IR vibrational transitions of C60 and C70 in emission are found in Spitzer IRS spectra of individual stars (LRLL 1, 2, 58), in the averaged spectrum of three other cluster stars (LRLL 21, 31 and 67) and in spectra obtained at four interstellar locations distributed across the IC 348 region. Fullerene bands appear widely distributed in this region with higher strength in the lines-of-sight of stars at the core of the cluster. Emission features consistent with three most intense bands of the C$_{60}^+$ and with one of C$_{60}^-$ are also found in several spectra, and if ascribed to these ionized species it would imply ionization fractions at 20 and 10 %, respectively. The stars under consideration host protoplanetary disks, however the spatial resolution of the spectra is not sufficient to disentangle the presence of fullerenes in them. If fullerene abundances in the cloud were representative of IC 348 protoplanetary disks, C60, the most abundant of the two species, could host ∼ 0.1 % of the total available carbon in the disks. This should encourage dedicated searches in young disks with upcoming facilities as JWST. Fullerenes provide a reservoir of pentagonal and hexagonal carbon rings which could be important as building blocks of prebiotic molecules. Accretion of these robust molecules in early phases of planet formation may contribute to the formation of complex organic molecules in young planets.

Synthesis of novel porphyrin and chlorin phosphonic acids and their immobilization on metal oxides

2011 ◽  
Vol 15 (09n10) ◽  
pp. 1070-1077 ◽  
Author(s):  
Martin Erbacher ◽  
Franz-Peter Montforts
Keyword(s):  
Metal Oxides ◽  
Phosphonic Acid ◽  
Self Assembled Monolayers ◽  
Phosphonic Acids ◽  
Amide Coupling ◽  
Vis Spectroscopy ◽  
Assembled Monolayers ◽  
Phosphonic Acid Groups ◽  
Hemin Chloride ◽  
Blood Pigment

In this study an easy and flexible access to porphyrin and chlorin phosphonic acids is presented. Novel types of phosphonic acid terminated porphyrins and chlorins were synthesized starting from commercially available red blood pigment hemin chloride. Phosphonic acid groups were linked to the porphyrinoids by amide coupling via appropriate spacer moieties. Self-assembled monolayers of the synthesized phosphonates on mesoporous TiO2 electrodes of approximately 3 μm thickness were formed. Surface concentrations in a range of 1 to 4 × 10-8 mol.cm-2 could be determined by UV-vis spectroscopy.

scholarly journals Silver-assisted gold-catalyzed formal synthesis of the anticoagulant Fondaparinux pentasaccharide

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Gulab Walke ◽  
Niteshlal Kasdekar ◽  
Yogesh Sutar ◽  
Srinivas Hotha
Keyword(s):  
Glucuronic Acid ◽  
Building Blocks ◽  
Process Efficiency ◽  
Reaction Conditions ◽  
Formal Synthesis ◽  
Iduronic Acid ◽  
Heparin Sulfate ◽  
Donor Acceptor ◽  
Selectivity Studies ◽  
First Time

AbstractClinically approved anti-coagulant Fondaparinux is safe since it has zero contamination problems often associated with animal based heparins. Fondaparinux is a synthetic pentasaccharide based on the antithrombin-binding domain of Heparin sulfate and contains glucosamine, glucuronic acid and iduronic acid in its sequence. Here, we show the formal synthesis of Fondaparinux pentasaccharide by performing all glycosidations in a catalytic fashion for the first time to the best of our knowledge. Designer monosaccharides were synthesized avoiding harsh reaction conditions or reagents. Further, those were subjected to reciprocal donor-acceptor selectivity studies to guide [Au]/[Ag]-catalytic glycosidations for assembling the pentasaccharide in a highly convergent [3 + 2] or [3 + 1 + 1] manner. Catalytic and mild activation during glycosidations that produce desired glycosides exclusively, scalable route to the synthesis of unnatural and expensive iduronic acid, minimal number of steps and facile purifications, shared use of functionalized building blocks and excellent process efficiency are the salient features.

scholarly journals Palladium-catalyzed selective oxidative amination of olefins with Lewis basic amines

2021 ◽  
Author(s):  
Yangbin Jin ◽  
Chunsheng Li ◽  
Meng Li ◽  
Wanqing Wu ◽  
Huanfeng Jiang
Keyword(s):  
Organic Molecules ◽  
Functional Materials ◽  
Building Blocks ◽  
Efficient Synthesis ◽  
Oxidative Amination ◽  
First Case ◽  
Palladium Catalyzed ◽  
Pharmaceutical Agents ◽  
Complex Organic ◽  
Tremendous Challenge

Abstract Amines are prominent in natural products, pharmaceutical agents, and agrochemicals. Moreover, they are synthetically valuable building blocks for the construction of complex organic molecules and functional materials. However, amines, especially aliphatic and aromatic amines with free N-H, are prone to coordinate with transition-metal and deactivating the catalyst, posing a tremendous challenge to the application of Lewis basic amines in the amination of olefins. Herein we present the first case of oxidative amination of simple olefins with various Lewis basic amines. The combination of a palladium catalyst, 2,6-dimethyl-1,4-benzoquinone (2,6-DMBQ), and a phosphorous ligand leads to the efficient synthesis of alkyl and aryl allylamines. A series of allylamines are obtained with good yields and excellent regio- and stereoselectivities. Intramolecular amination to synthesize tetrahydropyrrole and piperidine derivatives was also realized. Mechanistic investigations reveal that the reaction undergoes allylic C(sp3)-H activation and subsequent functionalization.

scholarly journals Metal-Free Photoredox Phosphonation of C–N and C–X Bonds in Aqueous Solvent Mixtures

2021 ◽  
Author(s):  
Lei Pan ◽  
Alexandra Kelley ◽  
Maria Victoria Cooke ◽  
Macy Deckert ◽  
Sébastien Laulhé
Keyword(s):  
Building Blocks ◽  
Solvent Mixture ◽  
Solvent Mixtures ◽  
Environmental Footprint ◽  
Reaction Conditions ◽  
Metal Free ◽  
Aqueous Solvent ◽  
Wide Range ◽  
Reaction Proceeds ◽  
Phosphonate Esters

Aryl phosphonate esters are valuable moieties for the pharmaceutical and agrochemical industries. Accessing such compounds from affordable and abundant phosphite reagents and a wide range of aromatic building blocks under metal-free, visible light-induced reaction conditions would represent a desirable technology. Herein, we present an efficient and mild methodology for the synthesis of aromatic phosphonate esters in good to excellent yields using DBU and phenothiazine as a photoredox catalyst. The reaction exhibits wide functional group compatibility enabling the transformation in presence of ketone, amide, ester, amine, and alcohol moieties. Importantly, the reaction proceeds using a green solvent mixture primarily composed of water, thus lowering the environmental footprint of this transformation compared to current methods.

scholarly journals Titan's Organic Chemistry

1985 ◽  
Vol 112 ◽  
pp. 107-121
Author(s):  
C. Sagan ◽  
W. R. Thompson ◽  
B. N. Khare
Keyword(s):  
Organic Chemistry ◽  
Solar System ◽  
Organic Molecules ◽  
Building Blocks ◽  
Organic Solids ◽  
Microwave Frequencies ◽  
Life On Earth ◽  
Complex Organic

Voyager discovered nine simple organic molecules in the atmosphere of Titan. Complex organic solids, called tholins, produced by irradiation of simulated Titanian atmosphere are consistent with measured properties of Titan from ultraviolet to microwave frequencies, and are the likely main constituents of the observed red aerosols. The tholins contain many of the organic building blocks central to life on Earth. At least 100 m and possibly kms thickness of complex organics have been produced on Titan during the age of the solar system, and may exist today as submarine deposits beneath an extensive ocean of simple hydrocarbons.

scholarly journals The ALMA-PILS survey: complex nitriles towards IRAS 16293–2422

2018 ◽  
Vol 616 ◽  
pp. A90 ◽  
Author(s):  
H. Calcutt ◽  
J. K. Jørgensen ◽  
H. S. P. Müller ◽  
L. E. Kristensen ◽  
A. Coutens ◽  
...  
Keyword(s):  
Organic Molecules ◽  
Functional Group ◽  
Evolutionary Stage ◽  
Warm Up ◽  
Star Forming ◽  
Star Forming Regions ◽  
Solar System Bodies ◽  
Using Data ◽  
First Time ◽  
Complex Organic

Context. Complex organic molecules are readily detected in the inner regions of the gaseous envelopes of forming protostars. Their detection is crucial to understanding the chemical evolution of the Universe and exploring the link between the early stages of star formation and the formation of solar system bodies, where complex organic molecules have been found in abundance. In particular, molecules that contain nitrogen are interesting due to the role nitrogen plays in the development of life and the compact scales such molecules have been found to trace around forming protostars. Aims. The goal of this work is to determine the inventory of one family of nitrogen-bearing organic molecules, complex nitriles (molecules with a –C≡N functional group) towards two hot corino sources in the low-mass protostellar binary IRAS 16293–2422. This work explores the abundance differences between the two sources, the isotopic ratios, and the spatial extent derived from molecules containing the nitrile functional group. Methods. Using data from the Protostellar Interferometric Line Survey (PILS) obtained with ALMA, we determine abundances and excitation temperatures for the detected nitriles. We also present a new method for determining the spatial structure of sources with high line density and large velocity gradients – Velocity-corrected INtegrated emission (VINE) maps. Results. We detect methyl cyanide (CH3CN) as well as five of its isotopologues, including CHD2CN, which is the first detection in the interstellar medium (ISM). We also detect ethyl cyanide (C2H5CN), vinyl cyanide (C2H3CN), and cyanoacetylene (HC3N). We find that abundances are similar between IRAS 16293A and IRAS 16293B on small scales except for vinyl cyanide which is only detected towards the latter source. This suggests an important difference between the sources either in their evolutionary stage or warm-up timescales. We also detect a spatially double-peaked emission for the first time in molecular emission in the A source, suggesting that this source is showing structure related to a rotating toroid of material. Conclusions. With high-resolution observations, we have been able to show for the first time a number of important similarities and differences in the nitrile chemistry in these objects. These illustrate the utility of nitriles as potential tracers of the physical conditions in star-forming regions.

scholarly journals Solid-state production of complex organic molecules: H-atom addition versus UV irradiation

2017 ◽  
Vol 13 (S332) ◽  
pp. 429-434
Author(s):  
K.-J. Chuang
Keyword(s):  
Organic Molecules ◽  
Methyl Formate ◽  
Cumulative Effect ◽  
Quantitative Comparison ◽  
Recombination Reaction ◽  
Laboratory Studies ◽  
State Production ◽  
Dust Grain ◽  
First Time ◽  
Complex Organic

AbstractComplex organic molecules (COMs) have been observed in comets, hot cores and cold dense regions of the interstellar medium. It is generally accepted that these COMs form on icy dust grain through the recombination reaction of radicals triggered by either energetic UV-photon or non-energetic H-atom addition processing. In this work, we present for the first time laboratory studies that allow for quantitative comparison of hydrogenation and UV-induced reactions as well as their cumulative effect in astronomically relevant CO:CH3OH=4:1 ice analogues. The formation of glycolaldehyde (GA) and ethylene glycol (EG) is confirmed in pure hydrogenation experiments at 14 K, except methyl formate (MF), which is only clearly observed in photolysis. The fractions for MF:GA:EG are 0 : (0.2-0.4) : (0.8-0.6) for pure hydrogenation, and 0.2 : 0.3 : 0.5 for UV involving experiments and can offer a diagnostic tool to derive the chemical origin of these species. The GA/EG ratios in the laboratory (0.3-1.5) compare well with observations toward different objects.

scholarly journals Anharmonic Vibrational Frequencies and Spectroscopic Constants for the Detection of Ethynol in Space

2021 ◽  
Vol 7 ◽  
Author(s):  
Jax D. Dallas ◽  
Brent R. Westbrook ◽  
Ryan C. Fortenberry
Keyword(s):  
Interstellar Medium ◽  
Organic Molecules ◽  
Building Blocks ◽  
Spectroscopic Constants ◽  
Simultaneous Formation ◽  
Water Ice ◽  
Molecular Building Blocks ◽  
High Level ◽  
Complex Organic ◽  
Quantum Chemical Computations

The ethynol (HCCOH) molecule has recently been shown to be present in simulated astrochemical ices possibly linking it to molecular building blocks for interstellar complex organic molecules like amino acids. The proposed reaction mechanism suggests the simultaneous formation of both ketene and ethynol from mixed carbon monoxide/water ice in simulated interstellar conditions. Rigorous anharmonic spectral data within both the IR and microwave regions are needed for possible detection of ethynol in the interstellar medium. This study provides the first such data for this molecule from high-level quantum chemical computations where experiment is currently lacking. Ethynol has a Beff comparable to, but distinct from acetonitrile at 9,652.1 MHz and three notable infrared features with two in the hydride stretching-regions and the C–C stretch at 2,212.8 cm−1. The ketene isomer has already been detected in the interstellar medium, and the possible detection of ethynol made possible by this work may lead to a deeper understanding of the proposed ice formation mechanism involving both species and how this relates to the molecular origins of life.

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