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Chemical Synthesis of Residue-Selectively 13C and 2H Double-Isotope-Labeled Oligosaccharides as Chemical Probes for the NMR-Based Conformational Analysis of Oligosaccharides

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The Journal of Organic Chemistry

The Journal of Organic Chemistry: Latest Articles (ACS Publications)
Authors: Hiroki Hamagami, Yoshiki Yamaguchi, and Hiroshi Tanaka
feedproxy.google.com/~r/acs/joceah/~3/LsOPvQgkz7E/acs.joc.0c01939

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Synthetic Factors Governing Access to Tris(β-diketimine) Cyclophanes versus Tripodal Tri-β-aminoenones

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The Journal of Organic Chemistry

The Journal of Organic Chemistry: Latest Articles (ACS Publications)
Authors: Mary C. Eaton, Brian J. Knight, Robin Brahmi, Ricardo B. Ferreira, Vincent J. Catalano, Arnold L. Rheingold, Ion Ghiviriga, and Leslie J. Murray
feedproxy.google.com/~r/acs/joceah/~3/hthvAvsyrfM/acs.joc.0c01708

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Synthesis of Constrained C‐Glycosyl Amino Acid Derivatives Involving 1,3‐Dipolar Cycloaddition of Cyclic Nitrone as Key Step

Synthesis of Constrained C‐Glycosyl Amino Acid Derivatives Involving 1,3‐Dipolar Cycloaddition of Cyclic Nitrone as Key Step

Original conformationally restricted C‐glycosyl amino acid derivatives in different series have been isolated following a two‐step strategy involving 1,3‐dipolar cycloaddition between l‐(–)‐menthone‐derived nitrone and C‐vinylglycosides as the key step. The cycloaddition reaction was highly regio‐ and stereoselective leading to corresponding cycloadducts in high yield. Simple cleavage of the chiral auxiliary allows preparing C‐glycosyl amino acid analogs.

An efficient two‐step strategy for the synthesis of constrained C‐glycosyl amino acid derivatives from C‐vinylglycosides involving a 1,3‐dipolar cycloaddition using l‐(–)‐menthone‐derived nitrone as the key step is described. After optimization of 1,3‐dipolar cycloaddition conditions, various C‐vinylglycosides were tested leading exclusively to one diastereoisomer of the corresponding cycloadduct in good to excellent yields. The total facial selectivity observed was also studied by DFT calculations. Original conformationally restricted C‐glycosyl amino acid derivatives (8 examples) were isolated after simple cleavage of the chiral auxiliary.

Wiley: European Journal of Organic Chemistry: Table of Contents
Authors: Florian Rouzier, Rosanne Sillé, Ophélie Montiège, Arnaud Tessier, Muriel Pipelier, Gilles Dujardin, Arnaud Martel, Arnaud Nourry, Stéphane Guillarme
doi.org/10.1002/ejoc.202001162

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Biomedical Hydrogels Fabricated Using Diels–Alder Crosslinking

Biomedical Hydrogels Fabricated Using Diels–Alder Crosslinking

The interest in Diels‐Alder conjugation for biomaterials development is constantly increasing. In this minireview we highlight how this one step reaction can be employed to develop drug delivery systems and scaffold for tissue engineering. An overview of recent examples is provided in which DA cycloaddition has been exploited under mild condition and eventually in presence of cells.

The Diels–Alder (DA) cycloaddition is one of the best methods for biomaterials conjugation to generate tools for biomedical applications. It is a biocompatible one‐step reaction, exploiting functional groups absent in natural biopolymers, doesn’t require catalysts, and doesn’t generate side products, an ideal “click reaction”. In this review we provide an overview on the recent examples in which the DA cycloaddition has been exploited in nanomedicine. Nanoparticles for drug delivery or diagnosis, and nanostructured biomaterials for regenerative medicine, have been efficiently generated exploiting the DA reaction to crosslink the polymeric components, in order to obtain nanoparticles or scaffolds with the required chemical and morphological properties, and to conjugate targeting agents or signalling molecules.

Wiley: European Journal of Organic Chemistry: Table of Contents
Authors: Francesca Cadamuro, Laura Russo, Francesco Nicotra
doi.org/10.1002/ejoc.202001042

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Tetrabromomethane as an Organic Catalyst: a Kinetic Study of CBr4‐Catalyzed Schiff Condensation

Tetrabromomethane as an Organic Catalyst: a Kinetic Study of CBr4‐Catalyzed Schiff Condensation

Tetrabromomethane enhances the aldehyde–acyl hydrazide condensation to give N‐acyl hydrazones. This simple, inexpensive, and commercially available halomethane provides up to 14‐fold acceleration of the Schiff reaction; the kinetic data indicate that the studied condensation exhibits the first order on CBr4.

Tetrabromomethane functions as an organic catalyst for non‐redox reactions of carbonyl species and, in particular, it enhances the aldehyde–acyl hydrazide condensation to give N‐acyl hydrazones. This simple, inexpensive, and commercially available halomethane provides up to 14‐fold acceleration of the Schiff reaction; the kinetic data indicate that the studied condensation exhibits the first order on CBr4. The catalytic activity of CBr4 is significantly higher than the activity of other halogen‐containing species, such as CHX3 or ArX (X = Cl, Br, I).

Wiley: European Journal of Organic Chemistry: Table of Contents
Authors: Sevilya N. Yunusova, Dmitrii S. Bolotin, Mikhail A. Vovk, Peter M. Tolstoy, Vadim Yu. Kukushkin
doi.org/10.1002/ejoc.202001180

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Deciphering the Biosynthetic Mechanism of Pelletierine in Lycopodium Alkaloid Biosynthesis

Organic Letters: Latest Articles (ACS Publications)
Authors: Juan Wang, Ze-Kun Zhang, Fang-Fang Jiang, Bo-Wen Qi, Ning Ding, Saw Yu Yu Hnin, Xiao Liu, Jun Li, Xiao-hui Wang, Peng-Fei Tu, Ikuro Abe, Hiroyuki Morita, and She-Po Shi
feedproxy.google.com/~r/acs/orlef7/~3/TPth2yT18yo/acs.orglett.0c03339

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Intramolecular Povarov Reactions for the Synthesis of Chromenopyridine Fused 2-Pyridone Polyheterocycles Binding to α-Synuclein and Amyloid-β Fibrils

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The Journal of Organic Chemistry

The Journal of Organic Chemistry: Latest Articles (ACS Publications)
Authors: Dan E. Adolfsson, Mohit Tyagi, Pardeep Singh, Adrian Deuschmann, Jörgen Ådén, Anna L. Gharibyan, Sanduni Wasana Jayaweera, Anders E. G. Lindgren, Anders Olofsson, and Fredrik Almqvist
feedproxy.google.com/~r/acs/joceah/~3/JwjtfwA88uE/acs.joc.0c01699

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Process Safety in the Pharmaceutical Industry—Part I: Thermal and Reaction Hazard Evaluation Processes and Techniques

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Organic Process Research & Development

Organic Process Research & Development: Latest Articles (ACS Publications)

Authors: Ayman D. Allian, Nisha P. Shah, Antonio C. Ferretti, Derek B. Brown, Stanley P. Kolis, and Jeffrey B. Sperry
feedproxy.google.com/~r/acs/oprdfk/~3/8PU4ADPfdn0/acs.oprd.0c00226

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