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Chan–Lam Coupling
The Chan–Lam coupling reaction, also known as the Chan–Evans–Lam coupling, is a cross-coupling reaction between an aryl boronic acid and an alcohol (chemistry), alcohol or an amine to form the corresponding secondary aryl amines or aryl ethers, respectively. The Chan–Lam coupling is catalyzed by copper complexes. It can be conducted open to air at room temperature. The more popular Buchwald–Hartwig coupling relies on the use of palladium. History Dominic Chan, David A. Evans, David Evans, and Patrick Lam published their work nearly simultaneously. The mechanism however remained uncertain for many years. Later developments by others extended the scope to include using carboxylic acids, giving aryl-ester products. Mechanism Analysis of the mechanism is complicated by the lability of copper reagents and the multicomponent nature of the reaction. The reaction proceeds via the formation of copper-aryl complexes. A copper(III)-aryl-alkoxide or copper(III)-aryl-amide intermedi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cross-coupling Reaction
In organic chemistry, a cross-coupling reaction is a reaction where two different fragments are joined. Cross-couplings are a subset of the more general coupling reactions. Often cross-coupling reactions require metal catalysts. One important reaction type is this: : (R, R' = organic fragments, usually aryl; M = main group center such as Li or MgX; X = halide) These reactions are used to form carbon–carbon bonds but also carbon-heteroatom bonds. Cross-coupling reaction are a subset of coupling reactions. Richard F. Heck, Ei-ichi Negishi, and Akira Suzuki were awarded the 2010 Nobel Prize in Chemistry for developing palladium-catalyzed coupling reactions. Mechanism Many mechanisms exist reflecting the myriad types of cross-couplings, including those that do not require metal catalysts. Often, however, cross-coupling refers to a metal-catalyzed reaction of a nucleophilic partner with an electrophilic partner. In such cases, the mechanism generally involves reduct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
