Search results
Results from the WOW.Com Content Network
The mechanism of the Stille reaction has been extensively studied. [11] [23] The catalytic cycle involves an oxidative addition of a halide or pseudohalide (2) to a palladium catalyst (1), transmetalation of 3 with an organotin reagent (4), and reductive elimination of 5 to yield the coupled product (7) and the regenerated palladium catalyst (1).
John Kenneth Stille (May 8, 1930 – July 19, 1989) was an American chemist who discovered the Stille reaction. He received B.A. and M.A. degrees from the University of Arizona before serving in the Navy during the Korean War. He received his Ph.D. from the University of Illinois, where he studied under Carl Shipp Marvel. [1]
The Horner–Wadsworth–Emmons (HWE) reaction is a chemical reaction used in organic chemistry of stabilized phosphonate carbanions with aldehydes (or ketones) to produce predominantly E-alkenes. [1] The Horner–Wadsworth–Emmons reaction. In 1958, Leopold Horner published a modified Wittig reaction using phosphonate-stabilized carbanions.
The reaction is named after Ei-ichi Negishi who was a co-recipient of the 2010 Nobel Prize in Chemistry for the discovery and development of this reaction. Negishi and coworkers originally investigated the cross-coupling of organoaluminum reagents in 1976 initially employing Ni and Pd as the transition metal catalysts, but noted that Ni ...
The Stille reaction has been used to make an antitumor agent, (±)-epi-jatrophone; [3] the Suzuki reaction has been used to make an antitumor agent, oximidine II; [4] the Sonogashira reaction has been used to make an anticancer drug, eniluracil; [5] and the Negishi reaction has been used to make the carotenoid β-carotene via a transmetalation ...
Heck Reaction Mechanism This cycle is not limited to vinyl compounds, in the Sonogashira coupling one of the reactants is an alkyne and in the Suzuki coupling the alkene is replaced by an aryl boronic acid and in the Stille reaction by an aryl stannane .
The reaction gained synthetic importance with the discovery that palladium complexes catalyze the reaction. The reaction is analogous to hydrosilylation and is a subset of hydroelementation. Hydrostannylation is a versatile route to organotin compounds, many of which are versatile synthetic intermediates, e.g. in Stille coupling. [citation needed]
Many mechanisms exist reflecting the myriad types of cross-couplings, including those that do not require metal catalysts. [7] Often, however, cross-coupling refers to a metal-catalyzed reaction of a nucleophilic partner with an electrophilic partner. Mechanism proposed for Kumada coupling (L = Ligand, Ar = Aryl).