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  2. N-Bromosuccinimide - Wikipedia

    en.wikipedia.org/wiki/N-Bromosuccinimide

    NBS will react with alkenes 1 in aqueous solvents to give bromohydrins 2. The preferred conditions are the portionwise addition of NBS to a solution of the alkene in 50% aqueous DMSO, DME, THF, or tert-butanol at 0 °C. [3] Formation of a bromonium ion and immediate attack by water gives strong Markovnikov addition and anti stereochemical ...

  3. Wohl–Ziegler bromination - Wikipedia

    en.wikipedia.org/wiki/Wohl–Ziegler_bromination

    The generation of NBS radicals depicted in the Bloomfield mechanism has been shown to be far more difficult than imagined when it was proposed, which is why it has failed as a proper model throughout the years; however, evidence suggests that the Bloomfield mechanism is still acceptable for the oxidation of alcohols using NBS. [10] In the ...

  4. Nucleophilic aromatic substitution - Wikipedia

    en.wikipedia.org/wiki/Nucleophilic_aromatic...

    The following is the reaction mechanism of a nucleophilic aromatic substitution of 2,4-dinitrochlorobenzene (1) in a basic solution in water. Nucleophilic aromatic substitution Since the nitro group is an activator toward nucleophilic substitution, and a meta director, it is able to stabilize the additional electron density (via resonance) when ...

  5. Ei mechanism - Wikipedia

    en.wikipedia.org/wiki/Ei_mechanism

    In organic chemistry, the E i mechanism (Elimination Internal/Intramolecular), also known as a thermal syn elimination or a pericyclic syn elimination, is a special type of elimination reaction in which two vicinal (adjacent) substituents on an alkane framework leave simultaneously via a cyclic transition state to form an alkene in a syn elimination. [1]

  6. Hydroamination - Wikipedia

    en.wikipedia.org/wiki/Hydroamination

    The mechanism of metal-catalyzed hydroamination has been well studied. [11] Particularly well studied is the organolanthanide catalyzed intramolecular hydroamination of alkenes. [23] First, the catalyst is activated by amide exchange, generating the active catalyst (i). Next, the alkene inserts into the Ln-N bond (ii). [24]

  7. Stevens rearrangement - Wikipedia

    en.wikipedia.org/wiki/Stevens_rearrangement

    The reaction mechanism of the Stevens rearrangement is one of the most controversial reaction mechanisms in organic chemistry. [4] Key in the reaction mechanism [5] [6] for the Stevens rearrangement (explained for the nitrogen reaction) is the formation of an ylide after deprotonation of the ammonium salt by a strong base.

  8. Understanding eligible expenses for HRAs, QSEHRAs, and ICHRAs

    www.aol.com/understanding-eligible-expenses-hras...

    HRAs, QSEHRAs, and ICHRAS. Understanding the differences in eligible expenses between HRAs, QSEHRAs, and ICHRAs can help businesses determine which type of plan best fits their needs.

  9. Click chemistry - Wikipedia

    en.wikipedia.org/wiki/Click_chemistry

    Trans-cycloalkenes (usually cyclooctenes) and other strained alkenes such as oxanorbornadiene react in click reactions with a number of partners including azides, tetrazines and tetrazoles. These reaction partners can interact specifically with the strained alkene, staying bioorthogonal to endogenous alkenes found in lipids, fatty acids ...