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  2. Integration by substitution - Wikipedia

    en.wikipedia.org/wiki/Integration_by_substitution

    In calculus, integration by substitution, also known as u-substitution, reverse chain rule or change of variables, [1] is a method for evaluating integrals and antiderivatives. It is the counterpart to the chain rule for differentiation , and can loosely be thought of as using the chain rule "backwards."

  3. Substitution reaction - Wikipedia

    en.wikipedia.org/wiki/Substitution_reaction

    Substitution reactions in organic chemistry are classified either as electrophilic or nucleophilic depending upon the reagent involved, whether a reactive intermediate involved in the reaction is a carbocation, a carbanion or a free radical, and whether the substrate is aliphatic or aromatic. Detailed understanding of a reaction type helps to ...

  4. Hammett equation - Wikipedia

    en.wikipedia.org/wiki/Hammett_equation

    In organic chemistry, the Hammett equation describes a linear free-energy relationship relating reaction rates and equilibrium constants for many reactions involving benzoic acid derivatives with meta- and para-substituents to each other with just two parameters: a substituent constant and a reaction constant.

  5. Arene substitution pattern - Wikipedia

    en.wikipedia.org/wiki/Arene_substitution_pattern

    In meta-substitution, the substituents occupy positions 1 and 3 (corresponding to R and meta in the diagram). In para-substitution, the substituents occupy the opposite ends (positions 1 and 4, corresponding to R and para in the diagram). The toluidines serve as an example for these three types of substitution.

  6. Neighbouring group participation - Wikipedia

    en.wikipedia.org/wiki/Neighbouring_group...

    In organic chemistry, neighbouring group participation (NGP, also known as anchimeric assistance) has been defined by the International Union of Pure and Applied Chemistry (IUPAC) as the interaction of a reaction centre with a lone pair of electrons in an atom or the electrons present in a sigma or pi bond contained within the parent molecule but not conjugated with the reaction centre.

  7. Reaction mechanism - Wikipedia

    en.wikipedia.org/wiki/Reaction_mechanism

    In chemistry, a reaction mechanism is the step by step sequence of elementary reactions by which overall chemical reaction occurs. [1] A chemical mechanism is a theoretical conjecture that tries to describe in detail what takes place at each stage of an overall chemical reaction. The detailed steps of a reaction are not observable in most cases.

  8. Substituent - Wikipedia

    en.wikipedia.org/wiki/Substituent

    In organic chemistry, a substituent is one or a group of atoms that replaces (one or more) atoms, thereby becoming a moiety in the resultant (new) molecule. [1] ( In organic chemistry and biochemistry, the terms substituent and functional group, as well as side chain and pendant group, are used almost interchangeably to describe those branches from the parent structure, [2] though certain ...

  9. N-Bromosuccinimide - Wikipedia

    en.wikipedia.org/wiki/N-Bromosuccinimide

    N-Bromosuccinimide or NBS is a chemical reagent used in radical substitution, electrophilic addition, and electrophilic substitution reactions in organic chemistry. NBS can be a convenient source of Br •, the bromine radical. [1]