- Alkene Hydrofunctionalization Reactions
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A reductive cross coupling reaction process for functionalization of a nucleophilic alkene can be achieved. The nucleophilic alkene and a nucleophilic cross coupling partner compound can be reacted in the presence of an oxidizable alcohol and a suitable catalyst to form a reductive coupling product. Various additives can also be useful to refine the process such as by mitigating certain undesirable intermediates, facilitating specific site selectivity for various substitutions or reaction sites, etc. Chiral additives can be optionally used which act to provide asymmetric catalysis, e.g. allow for regioselective and stereoselective production of reductive coupling products. A reductive cross coupling pathway can include oxidizing the oxidizable alcohol to form a catalyst hydride. The nucleophilic alkene can be inserted into the catalyst hydride to form a catalyst-alkyl intermediate. Further, the catalyst-alkyl intermediate can be transmetallized with the nucleophilic cross coupling partner compound to form a transmetallated intermediate. The catalyst can be reductively eliminated to form the reductive coupling product and a reduced catalyst. Finally, the reduced catalyst can be oxidized under aerobic conditions, for example with oxygen, to form the oxidized catalyst and subsequent repetition through the cyclic pathway.
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Page/Page column 5-7
(2009/04/24)
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- A new approach to carbon-carbon bond formation: development of aerobic Pd-catalyzed reductive coupling reactions of organometallic reagents and styrenes
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Alkenes are attractive starting materials for organic synthesis and the development of new selective functionalization reactions is desired. Previously, our laboratory discovered a unique Pd-catalyzed hydroalkoxylation reaction of styrenes containing a phenol. Based upon deuterium labeling experiments, a mechanism involving an aerobic alcohol oxidation coupled to alkene functionalization was proposed. These results inspired the development of a new Pd-catalyzed reductive coupling reaction of alkenes and organometallic reagents that generates a new carbon-carbon bond. Optimization of the conditions for the coupling of both organostannanes and organoboronic esters is described and the initial scope of the transformation is presented. Additionally, several mechanistic experiments are outlined and support the rationale for the development of the reaction based upon coupling alcohol oxidation to alkene functionalization.
- Gligorich, Keith M.,Iwai, Yasumasa,Cummings, Sarah A.,Sigman, Matthew S.
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experimental part
p. 5074 - 5083
(2009/12/01)
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- Simple and efficient metal-free hydroarylation and hydroalkylation using strongly acidic ion-exchange resin
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Higly efficient hydroarylation and hydroalkylation of styrenes with various arenes and 1,3-dicarbonyl compounds respectively have been developed using Amberlyst-15 as a heterogeneous catalyst. The excellent yields, short reaction times, and high selectivity are the advantages of this method. The C-H functionalization has been achieved here under metal-free conditions. Copyright
- Das, Biswanath,Krishnaiah, Martha,Laxminarayana, Keetha,Damodar, Kongara,Kumar, D. Nandan
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experimental part
p. 42 - 43
(2009/12/02)
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- Aerobic alcohol oxidation coupled to palladium-catalyzed alkene hydroarylation with boronic esters
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(Chemical Equation Presented) An oxidation exercise: An aerobic alcohol oxidation coupled with a regioselective palladium-catalyzed reductive functionalization of styrenes and arylboronic esters has been developed (see scheme). The mechanism is thought to proceed by initial oxidation of the solvent to generate a PdII-hydride species, which subsequently reacts with the alkene and arylboronic ester to ultimately generate a new C-C bond.
- Iwai, Yasumasa,Gligorich, Keith M.,Sigman, Matthew S.
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p. 3219 - 3222
(2008/12/23)
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- Palladium-catalyzed reductive coupling of styrenes and organostannanes under aerobic conditions
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We report a highly regioselective PdII-catalyzed reductive coupling of an alkene with an organostannane using a tandem alcohol oxidation under aerobic conditions. Both aryl- and vinylstannanes are competent coupling partners with a variety of s
- Gligorich, Keith M.,Cummings, Sarah A.,Sigman, Matthew S.
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p. 14193 - 14195
(2008/09/18)
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- Decarbonylative diarylation reaction of N-tosylated α-amino acids
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The reaction of various N-tosylated α-amino acids with arenes in the presence of sulfuric acid afforded the corresponding diarylated derivatives in moderate yields, which were generated via decarbonylative arylation followed by Friedel-Crafts reaction of the generated tosylamide derivatives.
- Seong, Mi Ra,Lee, Hong Jung,Kim, Jae Nyoung
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p. 6219 - 6222
(2007/10/03)
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