Tris(o-phenylenedioxy)cyclotriphosphazene as a Promoter for the Formation of Amide Bonds Between Aromatic Acids and Amines

The atom-efficient formation of amide bonds has emerged as a top-priority research field in organic synthesis, as amide bonds constitute the backbones of proteins and represent an important structural motif in drug molecules. Currently, the increasing demand for novel discoveries in this field has focused substantial attention on this challenging subject. Herein, the degradable 1,3,5-triazo-2,4,6-triphosphorine (TAP) motif is presented as a new condensation system for the dehydrative formation of amide bonds between diverse combinations of aromatic carboxylic acids and amines. The underlying reaction mechanism was investigated, and potential catalyst intermediates were characterized using 31P NMR spectroscopy and ESI mass spectrometry.

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Photosensitized Nickel Catalysis Enabled Silyl Radical Mediated Direct Activation of Carbamoyl Chlorides to Access (Hetero)aryl Carbamides

10.26434/chemrxiv-2021-1klwq ◽

2021 ◽

Author(s):

Sudip Maiti ◽

Sayan Roy ◽

Pintu Ghosh ◽

Debabrata Maiti

Keyword(s):

Structural Motif ◽

Ni Catalyst ◽

Nickel Catalysis ◽

Metal Catalysis ◽

Amide Bonds ◽

Aryl Chlorides ◽

Avant Garde ◽

Silyl Radical ◽

Direct Activation ◽

Drug Molecules

The transformation of a readily available molecule to a medicinally relevant functionality is the heart of organic synthesis which literally unfolds new direction in the field of drug discovery and development. Accordingly, synthetic chemistry fraternity is constantly striving to introduce a range of avant-garde techniques to construct an incredibly important fundamental entity like “amide bonds” which connect the amino acids in proteins and exist as a prevalent structural motif in biomolecules. In this context, we want to introduce the concept of cross-electrophile coupling by merging the photoredox and transition metal catalysis to construct carbamides from superabundant (hetero)aryl chlorides or bromides along with commercially feasible carbamoyl chlorides. However, there is barely any report on direct activation of carbamoyl chloride so far. To circumvent the challenge, we employ the intrinsic affinity of silyl radical species towards halogen atom to harness the carbamoyl radical directly from carbamoyl chlorides which is seemingly the first of its kind. The success of this protocol relies on the prior formation of ‘aryl halides to Ni-catalyst’ oxidative addition intermediate that assists in generation of the vital carbamoyl radical. The breadth of application of this technique is significantly demonstrated by the synthesis of a plethora of (hetero)aryl carbamides with diverse functionalities. As stated earlier, we outline the direct utility of this protocol by the late-stage amidation of halide containing drug molecules and pharmacophores.

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Synthesis and Characterization of Enantiopure Tribenzotriquinacene Dimers Bearing a Platinum-Diacetylene Unit

Synthesis ◽

10.1055/s-0037-1612122 ◽

2019 ◽

Vol 51 (10) ◽

pp. 2116-2121 ◽

Cited By ~ 2

Author(s):

Wen-Rong Xu ◽

Xin-Rui Wang ◽

Hak-Fun Chow ◽

Dietmar Kuck

Keyword(s):

Crystal Structure ◽

Mass Spectrometry ◽

31P Nmr ◽

Synthesis And Characterization ◽

31P Nmr Spectroscopy ◽

Enantiomerically Pure ◽

X Ray ◽

Esi Mass Spectrometry ◽

13C And 31P Nmr

A pair of enantiomerically pure metallodimers containing two deeply concave tribenzotriquinacene (TBTQ) units linked by a platinum-diacetylene unit were synthesized. Such linear metal-centered TBTQ dimers are considered as edges of metallosquares and metallocubes that bear four or eight mutually syn-oriented TBTQ bowls at their tips, respectively. The structures of the metallodimers were characterized by 1H, 13C and 31P NMR spectroscopy, ESI mass spectrometry, and circular dichroism. The single X-ray crystal structure of (+)-enantiomer confirmed the absolute configuration of the metallodimers and revealed an edge (tip-to-tip) length of 18.456 Å and an approximated syn-orientation of the two TBTQ bowls in the solid state.

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Copper Catalysts in the Synthesis of Five-membered N-polyheterocycles

Current Organic Synthesis ◽

10.2174/1570179415666180815144442 ◽

2018 ◽

Vol 15 (7) ◽

pp. 940-971 ◽

Cited By ~ 9

Author(s):

Navjeet Kaur

Keyword(s):

Transition Metal ◽

Organic Synthesis ◽

Copper Catalysts ◽

Research Field ◽

Chemoselective Synthesis ◽

Specialized Equipment ◽

Transition Metal Catalyzed ◽

Synthetic Methodologies ◽

Metal Catalyzed ◽

Traditional Approaches

Background: Due to significant biological activity associated with N-, O- and S-heterocycles, a number of reports for their synthesis have appeared in recent decades. Traditional approaches require expensive or highly specialized equipment or would be of limited use to the synthetic organic chemist due to their highly inconvenient approaches. This review summarizes the applications of copper catalysts with the emphasis on their synthetic applications for nitrogen bearing polyheterocylces. In summary, this review article describes the synthesis of a number of five-membered poly heterocyclic rings. Objective: Nowadays new approaches that employ atom-economical and efficient pathway have been developed. The researchers are following natural models to design and synthesize heterocycles. The transition metal catalyzed protocols have attracted the attention as compared to other synthetic methodologies because they use easily available substrates to build multiple substituted complicated molecules directly under mild conditions. In organic synthesis, constituted by transition metal catalyzed coupling transformations are one of the most powerful and useful protocols. The N-heterocycles are synthesized by this convenient and useful tool. Conclusion: The efficient and chemoselective synthesis of heterocycles by this technique has appeared as an important tool. This review shows a highly dynamic research field and the employment of copper catalysts in organic synthesis. Several strategies have been pointed out in the past few years, to meet more sustainable, efficient and environmentally benign chemical products and procedures. The catalytic strategies have been the focus of intense research because they avoid the use of toxic reagents. Among these catalytic strategies, highly rewarding and an important method in heterocycles synthesis is metal catalyzed synthesis.

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Metal and Non-Metal Catalysts in the Synthesis of Five-Membered S-Heterocycles

Current Organic Synthesis ◽

10.2174/1570179416666181207144430 ◽

2019 ◽

Vol 16 (2) ◽

pp. 258-275 ◽

Cited By ~ 2

Author(s):

Navjeet Kaur

Keyword(s):

Organic Synthesis ◽

Biological Activities ◽

Reaction Times ◽

Research Field ◽

Environmentally Benign ◽

Metal Catalyst ◽

Efficient Synthesis ◽

Heterocyclic Molecules ◽

The Past ◽

Harsh Conditions

Background:A wide variety of biological activities are exhibited by N, O and S containing heterocycles and recently, many reports appeared for the synthesis of these heterocycles. The synthesis of heterocycles with the help of metal and non-metal catalyst has become a highly rewarding and important method in organic synthesis. This review article concentrated on the synthesis of S-heterocylces in the presence of metal and non-metal catalyst. The synthesis of five-membered S-heterocycles is described here.Objective:There is a need for the development of rapid, efficient and versatile strategy for the synthesis of heterocyclic rings. Metal, non-metal and organocatalysis involving methods have gained prominence because traditional conditions have disadvantages such as long reaction times, harsh conditions and limited substrate scope.Conclusion:The metal-, non-metal-, and organocatalyst assisted organic synthesis is a highly dynamic research field. For ßthe chemoselective and efficient synthesis of heterocyclic molecules, this protocol has emerged as a powerful route. Various methodologies in the past few years have been pointed out to pursue more sustainable, efficient and environmentally benign procedures and products. Among these processes, the development of new protocols (catalysis), which avoided the use of toxic reagents, are the focus of intense research.

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Quantitative Determination of Krill Oil Composition by ATR-FTIR, NIR, and 31P NMR Spectroscopy

10.21748/am20.144 ◽

2020 ◽

Author(s):

Ashraf Ismail ◽

Sanaz Molaye Moghaddam ◽

Jean-Pierre MetabanzoulouSarya Aziz ◽

Jacqueline Sedman ◽

Mazen Bahadi

Keyword(s):

Nmr Spectroscopy ◽

Quantitative Determination ◽

31P Nmr ◽

31P Nmr Spectroscopy ◽

Krill Oil ◽

Oil Composition

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Enzymatic decomposition of a locked nucleoside phosphoramidate monitored by 31P NMR spectroscopy

Collection Symposium Series ◽

10.1135/css201414356 ◽

2014 ◽

Author(s):

Eliška Procházková ◽

Hubert Hřebabecký ◽

Radim Nencka ◽

Martin Dračínský

Keyword(s):

Nmr Spectroscopy ◽

31P Nmr ◽

31P Nmr Spectroscopy

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Effect of Dietary Magnesium on Post Mortem Phosphocreatine Utilization in Skeletal Muscle of Swine: A Non-Invasive Study Using 31P-NMR Spectroscopy

Acta Veterinaria Scandinavica ◽

10.1186/bf03548184 ◽

1993 ◽

Vol 34 (4) ◽

pp. 397-404

Author(s):

B. Moesgaard ◽

I. Errebo Larsen ◽

B. Quistorff ◽

I. Therkelsen ◽

V. Grøsfjeld Christensen ◽

...

Keyword(s):

Skeletal Muscle ◽

Nmr Spectroscopy ◽

31P Nmr ◽

31P Nmr Spectroscopy ◽

Post Mortem ◽

Non Invasive ◽

Dietary Magnesium

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Unravelling the dissolution mechanism of polyphosphate glasses by 31P NMR spectroscopy: ligand competition and reactivity of intermediate complexes

Dalton Transactions ◽

10.1039/d0dt03381b ◽

2021 ◽

Author(s):

Dahiana Andrea Avila Salazar ◽

Peter Bellstedt ◽

Atsuhiro Miura ◽

Yuki Oi ◽

Toshihiro Kasuga ◽

...

Keyword(s):

Nuclear Magnetic Resonance ◽

Solid State ◽

Nmr Spectroscopy ◽

Biomedical Applications ◽

Structural Changes ◽

31P Nmr ◽

Dissolution Mechanism ◽

31P Nmr Spectroscopy ◽

Glass Dissolution ◽

Polyphosphate Glasses

Phosphate glass dissolution can be tailored via compositional and subsequent structural changes, which is of interest for biomedical applications such as therapeutic ion delivery. Here, solid-state 31P nuclear magnetic resonance...

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