Search results
Results from the WOW.Com Content Network
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:
The most common type of coupling reaction is the cross coupling reaction. [1] [2] [3] Richard F. Heck, Ei-ichi Negishi, and Akira Suzuki were awarded the 2010 Nobel Prize in Chemistry for developing palladium-catalyzed cross coupling reactions. [4] [5] Broadly speaking, two types of coupling reactions are recognized:
In cross-coupling reactions, the component reagents are called cross-coupling partners or simply coupling partners. These reagents can be further classified according to their nucleophilic vs electrophilic character: R-X + R'-Y → R-R' + XY. Typically the electrophilic coupling partner (R-X) is an aryl halide, but triflates are also used ...
This reaction is notable for using organolithiums as opposed to other cross-coupling reactions which utilize various metal-carbon compounds (metal = tin, magnesium, boron, silicon, zinc). Since the production of these other coupling reagents relies heavily upon organolithiums (especially in the case of organozinc and organomagnesium compounds ...
Pd-catalyzed decarboxylative cross-coupling of aryl halides with potassium cyanoacetate, reported by Yeung et al. Contrarily to Cu-only systems, decarboxylative palladation is the rate-limiting step in the palladium catalytic cycle. [4] Decarboxylative cross-coupling of potassium polyfluorobenzoates, reported by Shang et al.
The Hiyama coupling is a palladium-catalyzed cross-coupling reaction of organosilanes with organic halides used in organic chemistry to form carbon–carbon bonds (C-C bonds). This reaction was discovered in 1988 by Tamejiro Hiyama and Yasuo Hatanaka as a method to form carbon-carbon bonds synthetically with chemo - and regioselectivity . [ 1 ]
The major drawback of the Negishi coupling, aside from its water and oxygen sensitivity, is its relative lack of functional group tolerance when compared to other cross-coupling reactions. [39] (−)-stemoamide is a natural product found in the root extracts of ‘’Stemona tuberosa’’.
The first example of organogermanes used in transition-metal-catalyzed cross-coupling reaction was reported in 2004. [1] However, due to the toxicity, low reactivity (compared with other Ar–[M] nucleophiles) and poor stability of ArGeCl 3, this reaction was demonstrated not to be synthetically applicable.