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- https://chem.libretexts.org/Bookshelves/Inorganic_Chemistry/Organometallic_Chemistry_(Evans)/04%3A_Fundamentals_of_Organometallic_Chemistry/4.09%3A_Oxidative_Addition_of_Polar_ReagentsRadicals are sometimes thought of as the bucking broncos of the chemistry world, and as such, radical mechanisms for oxidative additions are more difficult to control and less appealing. Most of the t...Radicals are sometimes thought of as the bucking broncos of the chemistry world, and as such, radical mechanisms for oxidative additions are more difficult to control and less appealing. Most of the trends and mechanisms associated with reductive elimination are simply the opposite of those for oxidative addition, so our discussions of reductive elimination will be fairly short.
- https://chem.libretexts.org/Courses/Providence_College/Organic_Chemistry_I/08%3A_Substitution_Reactions/8.05%3A_Nucleophilic_Substitution_-_2nd_OrderInstead, the formation of the σC−Nuc bond and the breaking of the σC−LG bond occur at the same time in what is known as a concerted mechanism. The reaction is 2 nd order because the rate...Instead, the formation of the σC−Nuc bond and the breaking of the σC−LG bond occur at the same time in what is known as a concerted mechanism. The reaction is 2 nd order because the rate of the reaction is dependent on the concentration of both the nucleophile AND the structure of the starting material. This means that the nucleophile must approach exactly 180° opposite of the direction of the leaving group, which is where the larger lobe of the σ∗C−X lies.
- https://chem.libretexts.org/Courses/Providence_College/Organic_Chemistry_I/10%3A_Addition_Reactions_of_Alkenes/10.02%3A_Concerted_CycloadditionsFor example, a [2+1] cycloaddition involves a 3-membered ring transition state where two atoms of the ring come from the alkene substrate (HOMO, nucleophile) and one atom of the ring comes from the el...For example, a [2+1] cycloaddition involves a 3-membered ring transition state where two atoms of the ring come from the alkene substrate (HOMO, nucleophile) and one atom of the ring comes from the electrophile. Because of the 5-membered ring transition state, the delivery of the two alcohol functional groups occurs from the same face of the alkene.
