Synthesis and functionalization of β-alkyl-meso-triarylcorroles

2015 ◽  
Vol 19 (07) ◽  
pp. 865-873 ◽  
Author(s):  
Giuseppe Pomarico ◽  
Manuela Stefanelli ◽  
Sara Nardis ◽  
Sara Lentini ◽  
Daniel O. Cicero ◽  
...  
Keyword(s):  
Good Yield ◽  
Cross Coupling ◽  
Methyl Groups ◽  
Macrocyclic Ring ◽  
Electronic Distribution ◽  
Synthetic Routes ◽  
Definition Of ◽  
Electron Withdrawing Substituents

After the definition of efficient synthetic routes for the preparation of triarylcorroles, the functionalization of these macrocycles is becoming a necessary and challenging field of research. One important synthetic step is the introduction of substituents able to influence the electronic distribution in the macrocyclic ring. A valuable target would be a corrole macrocycle with some β-pyrrole positions occupied by methyl groups, while exploiting other positions to introduce electron-withdrawing substituents. To explore the scope of this approach, we investigated the bromination and the nitration of the corrole ring and the desired products have been obtained in moderate to good yield. The successful preparation of selectively halogenated corroles is particularly interesting since they are suitable substrates for the preparation of more complex partially alkylated structures using modern cross coupling methodologies.

scholarly journals Modular synthesis of α-fluorinated arylmethanes via desulfonylative cross-coupling

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Masakazu Nambo ◽  
Jacky C.-H. Yim ◽  
Luiza B. O. Freitas ◽  
Yasuyo Tahara ◽  
Zachary T. Ariki ◽  
...  
Keyword(s):  
Biological Activity ◽  
Late Stage ◽  
Recent Progress ◽  
Cross Coupling ◽  
Biologically Active Compounds ◽  
Biologically Active ◽  
Active Compounds ◽  
Arylboronic Acids ◽  
Modular Synthesis ◽  
Synthetic Routes

Abstract α-Fluoromethylarenes are common substructures in pharmaceuticals and agrochemicals, with the introduction of fluorine often resulting in improved biological activity and stability. Despite recent progress, synthetic routes to α-fluorinated diarylmethanes are still rare. Herein we describe the Pd-catalyzed Suzuki-Miyaura cross-coupling of α-fluorinated benzylic triflones with arylboronic acids affording structurally diverse α-fluorinated diarylmethanes. The ease of synthesis of fluorinated triflones as the key starting materials enables powerful late-stage transformations of known biologically active compounds into fluorinated analogs.

Facile Buchwald–Hartwig coupling of sterically encumbered substrates effected by PNP ligands

2019 ◽  
Vol 48 (8) ◽  
pp. 2730-2734 ◽  
Author(s):  
Neha Kathewad ◽  
Anagha M. C. ◽  
Nasrina Parvin ◽  
Sneha Parambath ◽  
Pattiyil Parameswaran ◽  
...  
Keyword(s):  
Good Yield ◽  
Cross Coupling ◽  
Sterically Demanding ◽  
Palladium Catalyzed

We employed Ph2PN(Ar)PPh2 ligands for the palladium catalyzed C–N cross coupling of a variety of sterically demanding substrates and isolated very good yield of coupling products.

scholarly journals General Approach to the Total Synthesis of Macroline-Related Sarpagine and Ajmaline Alkaloids1

2008 ◽  
Vol 3 (11) ◽  
pp. 1934578X0800301
Author(s):  
Chitra R. Edwankar ◽  
Rahul V. Edwankar ◽  
Sundari Rallapalli ◽  
James M. Cook
Keyword(s):  
Total Synthesis ◽  
Cross Coupling ◽  
Complex Molecules ◽  
Coupling Process ◽  
Efficient Strategy ◽  
Synthetic Routes

Described in this review is a general and efficient strategy for the synthesis of macroline-related sarpagine and ajmaline alkaloids. The tetracyclic ketone in the parent system, as well as the alkoxy substituted series served as templates for the synthesis of these complex molecules. The palladium-mediated enolate cross coupling process, regiospecific hydroboration, and Tollens reaction are some of the key transformations that have been employed for further functionalization of these templates. Synthetic routes that have been improved, in order to obtain gram quantities of these alkaloids form a part of this review.

scholarly journals Opening up the Toolbox: Synthesis and Mechanisms of Phosphoramidates

Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3684 ◽  
Author(s):  
Emeka J. Itumoh ◽  
Shailja Data ◽  
Erin M. Leitao
Keyword(s):  
Organophosphorus Compounds ◽  
Cross Coupling ◽  
Important Class ◽  
Synthetic Routes ◽  
Opening Up

This review covers the main synthetic routes to and the corresponding mechanisms of phosphoramidate formation. The synthetic routes can be separated into six categories: salt elimination, oxidative cross-coupling, azide, reduction, hydrophosphinylation, and phosphoramidate-aldehyde-dienophile (PAD). Examples of some important compounds synthesized through these routes are provided. As an important class of organophosphorus compounds, the applications of phosphoramidate compounds, are also briefly introduced.

scholarly journals Crystal structures of three 4-substituted-2,2′-bipyridines synthesized by Sonogashira and Suzuki–Miyaura cross-coupling reactions

2017 ◽  
Vol 73 (4) ◽  
pp. 610-615
Author(s):  
Thuy Luong Thi Thu ◽  
Ngan Nguyen Bich ◽  
Hien Nguyen ◽  
Luc Van Meervelt
Keyword(s):  
Cross Coupling ◽  
Coupling Reactions ◽  
Acta Cryst ◽  
X Ray ◽  
Π Interactions ◽  
Cross Coupling Reactions ◽  
Synthetic Routes ◽  
Solvent Molecules ◽  
The Given ◽  
Crystal Packings

Facile synthetic routes for three 4-substituted 2,2′-bipyridine derivatives, 4-[2-(4-methylphenyl)ethynyl]-2,2′-bipyridine, C19H14N2, (I), 4-[2-(pyridin-3-yl)ethynyl]-2,2′-bipyridine, C17H11N3, (II), and 4-(indol-4-yl)-2,2′-bipyridine, C18H13N3, (III),viaSonogashira and Suzuki–Miyaura cross-coupling reactions, respectively, are described. As indicated by X-ray analysis, the 2,2′-bipyridine core, the ethylene linkage and the substituents of (I) and (II) are almost planar [dihedral angles between the two ring systems: 8.98 (5) and 9.90 (6)° for the two molecules of (I) in the asymmetric unit and 2.66 (14)° for (II)], allowing π-conjugation. On the contrary, in (III), the indole substituent ring is rotated significantly out of the bipyridine plane [dihedral angle = 55.82 (3)°], due to steric hindrance. The crystal packings of (I) and (II) are dominated by π–π interactions, resulting in layers of molecules parallel to (30-2) in (I) and columns of molecules along theaaxis in (II). The packing of (III) exhibits zigzag chains of molecules along thecaxis interacting through N—H...N hydrogen bonds and π–π interactions. The contributions of unknown disordered solvent molecules to the diffraction intensities in (II) were removed with the SQUEEZE [Spek (2015).Acta Cryst.C71, 9–18] algorithm ofPLATON. The given chemical formula and other crystal data do not take into account these solvent molecules.

scholarly journals Synthesis of new, highly luminescent bis(2,2’-bithiophen-5-yl) substituted 1,3,4-oxadiazole, 1,3,4-thiadiazole and 1,2,4-triazole

2014 ◽  
Vol 10 ◽  
pp. 1596-1602 ◽  
Author(s):  
Anastasia S Kostyuchenko ◽  
Vyacheslav L.Yurpalov ◽  
Aleksandra Kurowska ◽  
Wojciech Domagala ◽  
Adam Pron ◽  
...  
Keyword(s):  
Good Yield ◽  
Ring Closure ◽  
Quantum Yields ◽  
Synthetic Approach ◽  
Structural Elements ◽  
Target Molecule ◽  
Synthetic Strategy ◽  
Donor Acceptor ◽  
Synthetic Routes ◽  
Derivatives Of

A new synthetic approach towards the preparation of functionalised, soluble, donor–acceptor (DA) alkylbithiophene derivatives of oxadiazole, thiadiazole and triazole is reported. Taking advantage of the Fiesselmann reaction, reactive bithiophene synthons having alkyl or alkoxy substituents at designated positions are prepared. Following a synthetic strategy, featuring the bottom-up approach, sequential structural elements are built, starting from a simple thiophene compound, until the target molecule is obtained, all in good yield. Supplementing the well established methods of oxadiazole and thiadiazole synthesis, efficient ring closure reaction affording a 4H-1,2,4-triazole unit is presented. All target ambipolar compounds display strong photoluminescence with measured quantum yields up to 0.59. Modification of the demonstrated synthetic routes may be exploited for the preparation of longer, specifically functionalised oligothiophenes, coupled to other heteroaromatic cores.

Heterocyclic Amplifiers of Phleomycin. VI. Some Phenylpurines, Phenylpteridines, Phenylquinazolines and Related Compounds

1985 ◽  
Vol 38 (3) ◽  
pp. 467 ◽  
Author(s):  
DJ Brown ◽  
K Mori
Keyword(s):  
Side Chain ◽  
Methyl Groups ◽  
Bacterial System ◽  
Synthetic Routes ◽  
Related Compounds

Synthetic routes are described to a series of 2-, 6- and 8- phenylpurines , each with an appropriate S-or NH-linked side chain elsewhere in the molecule; to 2- and 4-phenylpteridines, each with a similar side chain and some with two additional C-methyl groups, to 2- and 4-phenylquinazolines, each equipped with an analogous side chain; and to two pyridinyl analogues of the above. Three of the above components are shown to have considerable activity as amplifiers of phleomycin -G in an in vitro bacterial system.

scholarly journals Synthetic routes to 1,3-divinyl cyclobutanes

1987 ◽  
Author(s):  
Σωτήριος Ιερόπουλος
Keyword(s):  
Metal Complexes ◽  
Good Yield ◽  
Room Temperature ◽  
Wittig Reaction ◽  
Organic Reactions ◽  
New Method ◽  
Cycloaddition Reactions ◽  
Facile Synthesis ◽  
Synthetic Routes ◽  
Ketone Ester

The chemistry of the cyclobutadiene metal complexes of the last decade is reviewed. Emphasis is given to the organic reactions involving the cyclobutadiene ligand. Dichoro, dimethyl, and diphenyl ketenes were used in [2+21-cycloaddition reactions with 1,3-dienes, which included 1-vinyl cyclohexene, 2-triethylsilylbuta-l,3-diene and 1- and 2- trimethylsilyloxybuta-1,3-dienes. Thecycloadditions were rarely found to be regiospecific and nearly always low yielding. The produced cyclobutanones were very often unstable. 2,2-Diphenyl-3-(1'-triethylsilyl-1'-ethenyl) cyclobutanone was prepared but it was found not to produce the expected 1,3-divinyl cyclobutan-l-ol when treated with vinylmagnesium bromide. 2,2-Dimethyl and 2,2-diphenyl-3-ethoxy cyclobutanones were prepared and their reactions with vinylmagnesium bromide and methyl lithium were investigated. Ethyl 4,4-diphenylbut-3-enoate was formed when 2,2-diphenyl-3-ethoxy cyclobutanone was treated with vinylmagnesium bromide. As well as the above ester, the same cyclobutanone gave 5,5-diphenylpent4-en-2-one when treated with methyl lithium. 2,2-Dimethyl3-ethoxy cyclobutanone gave the expected alcohols when reacted with the same two reagents. 1-(11-Phenyl-2'-propenyl)-2,2-dimethyl-3-vinyl cyclobutane was synthesised starting from a-pinene. The best route was found to involve the preparation of pinonic aldehyde by ozonolysis of q-pinene. The aldehyde was reduced to pinonic alcohol which was then converted to pinonic iodide by treatment with triphenylphosphine and iodine. The iodide was dehydrohalogenated by a new method, described in chapter six of the thesis, to givel-acetyl-2,2-dimethy1-3-vinyl cyclobutane. A subsequent Wittig reaction gave the desired divinyl cyclobutane. Finally, the development of a new methodology is described for the dehydrohalogenation of primary bromides and iodides. It involves a novel, facile synthesis of tetrakis(triphenylphosphine) nickel. The primary halide is mixed with 1,8-diazabicyclo[5.4.0lundec-7-ene and the mixture added to the low valent nickel reagent. The alkene was formed in good yield after twelve hours of stirring at room temperature under argon. The reaction was applied to a few halides and it was found to be compatible with alcohol, ketone, ester, and ether groups.

scholarly journals New Sustainable Synthetic Routes to Cyclic Oxyterpenes Using the Ecocatalyst Toolbox

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7194
Author(s):  
Camille Bihanic ◽  
Arthur Lasbleiz ◽  
Morgan Regnier ◽  
Eddy Petit ◽  
Pierre Le Blainvaux ◽  
...  
Keyword(s):  
Natural Products ◽  
Good Yield ◽  
Perillyl Alcohol ◽  
Sustainable Chemistry ◽  
Water Lettuce ◽  
Mild Conditions ◽  
Pharmaceutical Industries ◽  
Synthetic Routes ◽  
New Generation ◽  
Green Conditions

Cyclic oxyterpenes are natural products that are mostly used as fragrances, flavours and drugs by the cosmetic, food and pharmaceutical industries. However, only a few cyclic oxyterpenes are accessible via chemical syntheses, which are far from being ecofriendly. We report here the synthesis of six cyclic oxyterpenes derived from ß-pinene while respecting the principles of green and sustainable chemistry. Only natural or biosourced catalysts were used in mild conditions that were optimised for each synthesis. A new generation of ecocatalysts, derived from Mn-rich water lettuce, was prepared via green processes, characterised by MP-AES, XRPD and TEM analyses, and tested in catalysis. The epoxidation of ß-pinene led to the platform molecule, ß-pinene oxide, with a good yield, illustrating the efficacy of the new generation of ecocatalysts. The opening ß-pinene oxide was investigated in green conditions and led to new and regioselective syntheses of myrtenol, 7-hydroxy-α-terpineol and perillyl alcohol. Successive oxidations of perillyl alcohol could be performed using no hazardous oxidant and were controlled using the new generation of ecocatalysts generating perillaldehyde and cuminaldehyde.

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