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Showing 1 to 8 of 8 for “"nitrile oxides"”.
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Isoxazole Linked siRNA Cholesterol Conjugates by Catalyst Free Nitrile Oxide/Alkyne Cycloadditions
… dipolar cycloaddition chemistry of nitrones and nitrile oxides with alkene and alkyne dipolarophiles Chapter 2 presents the somewhat disappointing findings on the cycloaddition reactions of maleimides. Reactions with “simple” maleimides suffered from poor yield and/or poor diastereoselectivity, …
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Funktionalisierung von 6H-1,2-Oxazinen durch 1,3-dipolare Cycloadditionen und Halogenierungen
… of 6H-1,2-oxazines were performed with nitrile oxides, nitrile imines, nitrile ylides, diazoalkanes, azomethine ylides and a nitrone. High diastereoselectivity was observed, induced by the steric hindrance of the ethoxy group at the 6H-1,2-oxazines. The cycloadditions occur with high …
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Synthesis and evaluation of polystyrene based soluble polymeric supports for organic synthesis
… reactions between polymer bound alkenes and nitrile oxides generated in situ from their corresponding aldoximes. The cleaved ?2-isoxazoline compounds were tested for biological activity against Mycobacterium fortuitum. To compare the success of these linear polystyrene copolymers, some of the …
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Substituent Effects: A Computational Study on Stabilities of Cumulenes and Low Barrier Hydrogen Bonds
… and isocyanates and related systems-alkynes, nitriles and nitrile oxides is studied using the density functional theory (B3LYP, SVWN and BP86) and ab initio (HF, MP2) calculations at the 6-31G* basis set level. Using isodesmic reactions, correlation between stabilization energies of cumulenes …
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Cycloadditions to 1-azetines and 1-azetin-4-ones
… of 1,3-dipoles and dienes was investigated.Nitrile oxides (5) and nitrile ylides (7) were found to add smoothly to the 1-azetine systems to yield the bicyclic adducts (6) and (8) respectively.Nitrile imines (9) also add to 1-azetines in a similar fashion to yield the bi-cyclic adduct (10). …
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Site-Specific Labelling of Nucleic Acids by Catalyst-Free 1,3-Dipolar Cycloadditions
… 1,3-dipolar cycloaddition reactions. Both nitrile oxide-alkyne cycloadditions (NOAC) and strain-promoted azide-alkyne cycloadditions (SPAAC) were explored. The possiblitity for ‘pre-synthetic’ functionalisation was demonstrated using non-nucleosidic phorphoramidite building blocks generated …
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ΜΕΛΕΤΗ ΑΝΤΙΔΡΑΣΕΩΝ 1,3-ΔΙΠΟΛΙΚΗΣ ΚΥΚΛΟΠΡΟΣΘΗΚΗΣ ΣΕ ΕΤΕΡΟΚΥΚΛΙΚΑ ΣΥΣΤΗΜΑΤΑ
… WITH STABLE NITRILE OXIDES AND NITRILIMINES TO AFFORD SPIRO CYCLOADDUCTS, BY ADDITION OF THE DIPOLE ON THE EXOCYCLIC DOUBLE BOND. THE REACTIONS ARE STEREOSPECIFIC AND REGIOSELECTIVE, GIVING IN ALL CASES ONLY ONE REGIOISOMER, IN WHICH THE ANIONIC CENTER OF THE …
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Synthesis Towards Fulminic Acid and Its Derivatives in 1, 3-Dipolar Cycloaddition Reactions.
<p>A new approach to fulminic acid cycloadditions has been developed. At reduced temperatures, fulminic acid is generated <em>in situ</em> and undergoes 1, 3-diploar cycloaddition reactions with dipolarophiles to form isoxazolines and/or its dimers. This procedure represents a novel, safe general …