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  2. Pyridinium - Wikipedia

    en.wikipedia.org/wiki/Pyridinium

    Pyridinium refers to the cation [C 5 H 5 NH] +. It is the conjugate acid of pyridine . Many related cations are known involving substituted pyridines, e.g. picolines, lutidines, collidines.

  3. Ylide - Wikipedia

    en.wikipedia.org/wiki/Ylide

    An ylide (/ ˈ ɪ l aɪ d /) [1] or ylid (/ ˈ ɪ l ɪ d /) is a neutral dipolar molecule containing a formally negatively charged atom (usually a carbanion) directly attached to a heteroatom with a formal positive charge (usually nitrogen, phosphorus or sulfur), and in which both atoms have full octets of electrons.

  4. Oxidation with chromium(VI) complexes - Wikipedia

    en.wikipedia.org/wiki/Oxidation_with_chromium(VI...

    Cr(VI)-pyridine and pyridinium reagents have the advantage that they are soluble in organic solvents as are the alcohol substrates. One family of reagents employs the complex CrO 3 (pyridine) 2. [2] Sarett's reagent: a solution of CrO 3 (pyridine) 2 in pyridine. It was popularized for selective oxidation of primary and secondary alcohols to ...

  5. Pyridinium p-toluenesulfonate - Wikipedia

    en.wikipedia.org/wiki/Pyridinium_p-toluenesulfonate

    In organic synthesis, PPTS is used as a weakly acidic catalyst, providing an organic soluble source of pyridinium (C 5 H 5 NH +) ions.For example, PPTS is used to deprotect silyl ethers or tetrahydropyranyl ethers when a substrate is unstable to stronger acid catalysts.

  6. Phenol oxidation with hypervalent iodine reagents - Wikipedia

    en.wikipedia.org/wiki/Phenol_oxidation_with...

    Phenol oxidation with hypervalent iodine reagents leads to the formation of quinone-type products or iodonium ylides, depending on the structure of the phenol. Trapping of either product is possible with a suitable reagent, and this method is often employed in tandem with a second process. [1]

  7. Acyl group - Wikipedia

    en.wikipedia.org/wiki/Acyl_group

    (R 1, R 2 and R 3 stands for organyl substituent or hydrogen in the case of R 1) In chemistry, an acyl group is a moiety derived by the removal of one or more hydroxyl groups from an oxoacid, [1] including inorganic acids. It contains a double-bonded oxygen atom and an organyl group (R−C=O) or hydrogen in the case of formyl group (H−C=O).

  8. Persistent radical effect - Wikipedia

    en.wikipedia.org/wiki/Persistent_radical_effect

    The persistent radical effect (PRE) in chemistry describes and explains the selective product formation found in certain free-radical cross-reactions. In these type of reactions, different radicals compete in secondary reactions. The so-called persistent (long-lived) radicals do not self-terminate and only react in cross-couplings.

  9. Pyridinium chlorochromate - Wikipedia

    en.wikipedia.org/wiki/Pyridinium_chlorochromate

    Pyridinium chlorochromate in a vial. Pyridinium chlorochromate (PCC) is a yellow-orange salt with the formula [C 5 H 5 NH] + [CrO 3 Cl] −. It is a reagent in organic synthesis used primarily for oxidation of alcohols to form carbonyls. A variety of related compounds are known with similar reactivity.