97632-25-2Relevant articles and documents
Stereoselective synthesis of (Z)-1-alkylseleno-1-alkenes by Ni-catalyzed coupling reaction of (Z)-dialkylselenoethenes with organozinc halides
Huang, Xian,Sun, Ai Ming
, p. 2725 - 2731 (1997)
(Z)-Dialkylselenoethenes 2, prepared conveniently from the hydrozirconation of dialkylselenoacetylenes 1 with Cp2Zr (H)Cl in THF followed by protonolysis, react readily at -10°C in THF with organozinc halides in the presence of a catalytic amou
Chemo- and regioselective reductive transposition of allylic alcohol derivatives via iridium or rhodium catalysis
Lundgren, Rylan J.,Thomas, Bryce N.
supporting information, p. 958 - 961 (2016/01/20)
We report highly chemo- and regioselective reductive transpositions of methyl carbonates to furnish olefin products with complementary regioselectivity to that of established Pd-catalysis. These Rh- and Ir-catalysed transformations proceed under mild conditions and enable selective deoxygenation in the presence of functional groups that are susceptible to reduction by metal hydrides.
Ligand Control of E/Z Selectivity in Nickel-Catalyzed Transfer Hydrogenative Alkyne Semireduction
Richmond, Edward,Moran, Joseph
, p. 6922 - 6929 (2015/10/05)
A nickel-catalyzed transfer hydrogenative alkyne semireduction protocol that can be applied to both internal and terminal alkynes using formic acid and Zn as the terminal reductants has been developed. In the case of internal alkynes, the (E)- or (Z)-olefin isomer can be accessed selectively under the same reaction conditions by judicious inclusion of a triphos ligand.
Convenient transfer semihydrogenation methodology for alkynes using a PdII-NHC precatalyst
Drost, Ruben M.,Bouwens, Tessel,Van Leest, Nicolaas P.,De Bruin, Bas,Elsevier, Cornelis J.
, p. 1349 - 1357 (2014/05/20)
A convenient and easy-to-use protocol for the Z-selective transfer semihydrogenation of alkynes was developed, using ammonium formate as the hydrogen source and the easily prepared and commercially available, highly stable complex PdCl(η3-C3H5)(IMes) (1) as the (pre)catalyst. Combined with triphenyl posphine as an additional ligand, this system provides a robust catalytic synthetic method that shows little to no over-reduction or isomerization after full substrate conversion. The system allows the direct use of solvents and reagents, as received from the supplier without drying or purification, thus providing a practical method for semihydrogenation of a broad range of alkynes. The mechanism behind these high and enhanced selectivities was determined through a set of kinetic experiments.
Bidentate hydroxyalkyl NHC ligands for the copper-catalyzed asymmetric allylic substitution of allyl phosphates with grignard reagents
Magrez, Magaly,Le Guen, Yann,Basle, Olivier,Crevisy, Christophe,Mauduit, Marc
supporting information, p. 1199 - 1203 (2013/02/25)
Demonstrating their potential: Bidentate alkoxy NHC ligands have been used in the copper-catalyzed asymmetric allylic alkylation of allyl phosphates with Grignard reagents (see scheme). The method provides access to tertiary and quaternary chiral centers with high regio- and enantioselectivity. The system is also applied to the synthesis of chiral E,E-dienes, a key structural motif prevalent in natural products. Copyright
Iron-catalysed, hydride-mediated reductive cross-coupling of vinyl halides and Grignard reagents
Le Bailly, Bryden A. F.,Greenhalgh, Mark D.,Thomas, Stephen P.
supporting information; experimental part, p. 1580 - 1582 (2012/03/26)
An iron-catalysed, hydride-mediated reductive cross-coupling reaction has been developed for the preparation of alkanes. Using a bench-stable iron(ii) pre-catalyst, reductive cross-coupling of vinyl iodides, bromides and chlorides with aryl- and alkyl Grignard reagents successfully gave the products of formal sp3-sp3 cross-coupling reactions.
Palladium-catalyzed allyl cross-coupling reactions with in situ generated organoindium reagents
Lee, Kooyeon,Kim, Hyunseok,Mo, Juntae,Lee, Phil Ho
scheme or table, p. 2147 - 2157 (2011/10/31)
Inter- and intramolecular palladium-catalyzed allyl cross-coupling reactions, using allylindium generated in situ from allyl halides and indium, is demonstrated. Allylindium compounds may be effective nucleophilic coupling partners in palladium-catalyzed cross-coupling reactions. A variety of allyl halides, such as allyl iodide, allyl bromide, crotyl bromide, prenyl bromide, geranyl bromide, and 3-bromocyclohexene afforded the allylic cross-coupling products in good to excellent yields. Stereochemistry of the double bond is retained in the allylic cross-coupling reactions. Electrophilic cross-coupling partners, such as aryl and vinyl halides, dibromoolefin, alkynyl iodide, and aryl and vinyl triflates participate in these reactions. The presence of various substituents, such as n-butyl, ketal, acetyl, ethoxycarbonyl, nitrile, N-phenylamido, nitro, and chloride groups on the aromatic ring of electrophilic coupling partners showed little effect on the efficiency of the reactions. The present conditions work equally well for not only intermolecular but also intramolecular palladium-catalyzed cross-coupling reactions. These methods provide an efficient synthetic method for the introduction of an allyl group, which can be easily further functionalized to afford an sp2- and sp-hybridized carbon. The present method complements existing synthetic methods as a result of advantageous features such as easy preparation and handling, thermal stability, high reactivity and selectivity, operational simplicity, and low toxicity of allylindium reagents.
Amphoteric α-boryl aldehydes
He, Zhi,Yudin, Andrei K.
supporting information; experimental part, p. 13770 - 13773 (2011/10/05)
A new class of stable molecules, α-boryl aldehydes, has been prepared from oxiranyl N-methyliminodiacetyl boronates by a 1,2-boryl migration with concomitant epoxide scission. A range of boryl imines, alkenes, alcohols, acids, enol ethers, enamides, and other functionalized boronic acid derivatives that are difficult or impossible to prepare using established protocols can be accessed from α-boryl aldehydes. The chemoselective transformations of these building blocks, including the facile synthesis of functionalized unnatural amino acids from silyloxy and amido vinyl boronates, attest to the potential of α-boryl aldehydes in chemical synthesis.
New method for cycloalumination of disubstituted acetylenes with 1,2-dichloroethane
Ramazanov,Ibragimov,Dzhemilev
scheme or table, p. 781 - 784 (2009/06/28)
A new procedure has been developed for the synthesis of 2,3-dialkyl(phenyl)aluminacyclopent-2-enes by Cp2TiCl 2-catalyzed cycloalumination of disubstituted acetylenes with EtAlCl2 in the presence of ethylene generated in situ from 1,2-dichloroethane and activated magnesium.
Cross-coupling reaction of allylic and benzylic carbonates with organo[2-(hydroxymethyl)phenyl]dimethylsilanes
Nakao, Yoshiaki,Ebata, Shiro,Chen, Jinshui,Imanaka, Hidekazu,Hiyama, Tamejiro
, p. 606 - 607 (2008/02/07)
The title reaction is found to proceed in the presence of a palladium catalyst and in the absence of any activator. Various functional groups are tolerated to give a diverse range of 1,4-diene and diarylmethane products, which are ubiquitous units of natural products and pharmaceuticals. Copyright
