223245-66-7Relevant academic research and scientific papers
Asymmetric Conjugate Addition of Grignard Reagents to 3-Silyl Unsaturated Esters for the Facile Preparation of Enantioenriched β-Silylcarbonyl Compounds and Allylic Silanes
Zhao, Kai,Loh, Teck-Peng
, p. 16764 - 16772 (2014)
A highly enantioselective conjugate addition of Grignard reagents to 3-silyl unsaturated esters to deliver synthetically useful chiral β-silylcarbonyl compounds was developed. The synthetic value of this methodology was further illustrated by the synthesis of enantioenriched β-hydroxyl esters and the facile access granted to various α-chiral allylic silanes. A plethora of diastereoselective transformations of β-silylenolates were also investigated and afforded manifold organosilanes that contained contiguous stereogenic centers with excellent enantioselectivity.
Copper-Catalyzed Silylcupration of Activated Alkynes
Vercruysse, Sébastien,Jouvin, Kévin,Riant, Olivier,Evano, Gwilherm
, p. 3373 - 3381 (2016/09/12)
A highly efficient catalytic silylcupration of activated alkynes is reported. Upon reaction with silylboronates and methanol in THF at room temperature in the presence of copper(I) fluoride tris(triphenylphosphine), a range of ynamides and propiolates were found to undergo a smooth silylcupration. This reaction, which tolerates various functional groups, affords a straightforward and efficient entry to the corresponding β-silylenamides and -acrylates, which were formed with high levels of regio- and stereoselectivities.
Stereoselective silylcupration of conjugated alkynes in water at room temperature
Linstadt, Roscoe T. H.,Peterson, Carl A.,Lippincott, Daniel J.,Jette, Carina I.,Lipshutz, Bruce H.
supporting information, p. 4159 - 4163 (2014/05/06)
Micellar catalysis enables copper-catalyzed silylcupration of a variety of electron-deficient alkynes, thereby providing access to isomerically pure E- or Z-β-silyl-substituted carbonyl derivatives. These reactions take place in minutes, afford high yields and stereoselectivity, and are especially tolerant of functional groups present in the substrates. The aqueous reaction medium has been successfully recycled several times, and a substrate/catalyst ratio of 10,000:1 has been documented for this methodology. Fast, cheap, and green: Micellar catalysis enables the selective construction of a variety β-silyl-substituted carbonyl derivatives under mild aqueous conditions. The reaction is catalyzed by low levels of CuI, is compatible with numerous electron-withdrawing groups, affords high yields, and provides opportunities for scale-up and recycling of the reaction medium. The environmental impact, as measured by E Factors, is very low.
Copper(II)-catalyzed silylation of activated alkynes in water: Diastereodivergent access to E- or Z-β-silyl-α,β-unsaturated carbonyl and carboxyl compounds
Calderone, Joseph A.,Santos, Webster L.
supporting information, p. 4154 - 4158 (2014/05/06)
Copper(II)-catalyzed silylation of substituted alkynylcarbonyl compounds was investigated. Through the activation of Me2PhSiBpin in water at room temperature and open atmosphere, vinylsilanes conjugated to carbonyl groups are synthesized in high yield. A surprising diastereodivergent access to olefin geometry was discovered using a silyl conjugate addition strategy: aldehydes and ketones were Z selective while esters and amides were exclusively transformed into the E products. Dial a diastereomer: The title reaction proceeds through the activation of Me2PhSiBpin in water at room temperature and open atmosphere to produce high yields of vinylsilanes conjugated to carbonyl groups. A surprising diastereodivergent access to olefin geometry was discovered using this silyl conjugate addition strategy: aldehydes were Z selective while esters and amides exclusively delivered the E-configured products.
Activation of Si-Si bonds for copper(I)-catalyzed conjugate silylation
Iannazzo, Laura,Molander, Gary A.
, p. 4923 - 4926,4 (2020/08/24)
Several alkyl- and vinylsilanes were prepared through the copper(I)-catalyzed conjugate silylation of α,β-unsaturated compounds. Optimal reaction conditions were first investigated to realize the conjugate addition of a nucleophilic silicon species to poo
Reactions of phenyldimethylsilyllithium with β-N,N- dimethylaminoenones: A convenient synthesis of β-dimethyl(phenyl) silylacrylic acid and its derivatives
Fleming, Ian,Marangon, Elena,Roni, Chiara,Russell, Matthew G.,Chamudis, Sandra Taliansky
, p. 325 - 332 (2007/10/03)
Phenyldimethylsilyllithium reacted with 5,5-dimethyl-3-(N,N,-dimethylamino) cyclohex-2-enone (7), 3-(E)-N,N-dimethylaminopropenal (11), and 4-N,N-dimethylaminobut-3-en-2-one (13) to give the corresponding β-silyl-α,β-unsaturated carbonyl compounds 8, 12, and 14, in which the dimethylamino group has been displaced by the phenyldimethylsilyl group. Phenyldimethylsilyllithium reacted with ethyl β-N,N- dimethylaminopropenoate (15) by conjugate addition, but, in contrast to the ketones 7 and 13 and the aldehyde 11, the intermediate enolate 16 was C-protonated in the aqueous work-up to give ethyl 3-N,N-dimethylamino-3- dimethyl(phenyl)silylpropanoate (17). When the enolate 16 was instead given a mysteriously brief treatment with methyl iodide before work-up, the product was ethyl 3-(E)-dimethy(phenyl)silylpropenoate (18). Phenyllithium and methyllithium also added conjugatively to ethyl β-N,N-dimethylaminoacrylate (15) but, in contrast to the silyl case, the intermediate enolate 22 reacted unexceptionally with methyl iodide to give the products 25 and 26 of stereoselective C-methylation. This synthesis of the ester 18 was used to synthesize the Oppolzer sultam derivative 30.
Reactions of phenyldimethylsilyllithium with β-N,N-dimethylaminoenones
Fleming, Ian,Marangon, Elena,Roni, Chiara,Russell, Matthew G.,Chamudis, Sandra Taliansky
, p. 200 - 201 (2007/10/03)
Phenyldimethylsilyllithium reacts with the β-N,N-dimethylaminoenones 1 and 7, with the enal 5, and with ethyl β-N,N-dimethylaminoacrylate 9 to give the corresponding α,β-unsaturated carbonyl compounds with a β-phenyldimethylsilyl group, but in the last ca
