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Showing 1 to 9 of 9 for “"alkynylation"”.
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Stereospecific alkynylation at the more hindered carbon of trisubstituted epoxides and concise syntheses of bis-THF acetogenins and analogues
Alkynyl aluminate reagents react cleanly at the tertiary position of trisubstituted epoxides in 75-80% isolated yield. The reaction is stereospecific with inversion at the substitution center. This work constitutes the first general method for the addition of a carbon nucleophile at the more …
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Synthesis of 3-aminocyclobutenones via [2 + 2] cycloaddition of ynamides and ketenes
… from amine derivatives by copper-catalyzed N-alkynylation with acetylenic bromides. The alkynylation reaction provides access to thermally sensitive compounds such as diynamides. Synthesis of the requisite halo diynes is achieved by Sonogashira coupling followed by base-mediated elimination at …
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Synthesis of indolines and indoles via intramolecular [4 + 2] cycloaddition of ynamides and conjugated enynes ; Synthesis of nitrogen heterocycles in supercritical carbon dioxide
A general amination strategy for the N-alkynylation of carbamates, sulfonamides, and chiral oxazolidinones and imidazolidinones is described. A variety of substituted ynamides are available by deprotonation of amide derivatives with KHMDS followed by reaction with CuI and an alkynyl halide. …
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C(sp2)–H Functionalizations Employing 2-Aminophenyl-1H-pyrazole as a New Removable Directing Group
… regio-selective hydroxylation, and ortho-alkynylation/annulation by using Cu(OAc)2 as an oxidant. </p>
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Annulation strategies for the synthesis of azulenes and polycyclic nitrogen heterocycles
… which are synthesized via the strategy for the N-alkynylation of amides strategy developed in the Danheiser laboratory. The products of these benzannulation reactions, highly-substituted anilines, then participate in ring closing metathesis reactions to form various nitrogen heterocycles. In …
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Expanding the structural diversity of discrete polymers accessible through iterative exponential growth
… of a novel allylation methodology. Using alkynylation of epichlorohydrin, LiBr Finkelstein, and TfOH-promoted allylation, we have been able to prepare a monomer for 3A (number of carbons in each polymer repeat unit, excluding alkyne) IEG in just three steps. Furthermore, the same reactions …
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Pyrrolo[2,3-d]pyrimidine-based π-conjugated fluorophores with 1,2,3-triazole and ethynyl linkers: synthesis and photophysical properties /
… emerged as suitable catalyst system for Stille alkynylation and arylation reactions providing the desired products in good yields. The developed protocol allows a wide library of novel 2-aryl-4-(arylethynyl)pyrrolo[2,3-d]pyrimidines and 2,4-bis(arylethynyl)pyrrolo[2,3-d]pyrimidines to be …
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Pirolo[2,3-d]pirimidino π-konjuguotų fluoroforų, turinčių 1,2,3-triazolo ir etinil jungtukus, sintezė ir fotofizikinės savybės /
… emerged as suitable catalyst system for Stille alkynylation and arylation reactions providing the desired products in good yields. The developed protocol allows a wide library of novel 2-aryl-4-(arylethynyl)pyrrolo[2,3-d]pyrimidines and 2,4-bis(arylethynyl)pyrrolo[2,3-d]pyrimidines to be …
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Direct Brønsted acid-catalyzed functionalization of benzhydryl alcohols and 2-ethoxytetrahydrofuran using potassium trifluoroborate salts
Metal-free transformations of organotrifluoroborates are advantageous since they avoid using frequently expensive and sensitive transition metals. Lewis acid-catalyzed reactions involving organotrifluoroborates have emerged as an alternative to metal-catalyzed protocols. However, these methods rely …