- A convenient synthesis of z-allylsilanes with good stereoselectivity promoted by samarium diiodide
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Synthesis of Z-allylsilanes in high or good yields and with good stereoselectivity is achieved from O-acetylated 1-silyl-3-chloro alcohols promoted by SmI2. The starting compounds were easily prepared from 2-chloroaldehydes and a mechanism is p
- Concellón, José M.,Rodríguez-Solla, Humberto,Simal, Carmen,Gómez, Cecilia
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- TfO-···H-O-H Interaction-Assisted Generation of a Silicon Cation from Allylsilanes: Access to Phenylallyl Ferrier Glycosides from Glycals
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We demonstrate here that the strained and bulky protonated 2,4,6-tri-tert-butylpyridine (TTBPy) triflate salt serves as a mild and efficient organocatalyst for the diastereoselective C-Ferrier glycosylation of various glycals. The importance of the role of the 1/2 H2O molecule trapped in the catalyst has been disclosed. The mechanism of action involves unique anionic triflate and H2O hydrogen-bond interactions that assist the activation of allylsilanes, providing unprecedented access to diastereoselective phenylallyl Ferrier glycosides.
- Addanki, Rupa Bai,Halder, Suvendu,Kancharla, Pavan K.
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supporting information
(2022/02/23)
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- Three-Component Visible-Light-Induced Palladium-Catalyzed 1,2-Alkyl Carbamoylation/Cyanation of Alkenes
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A mild visible-light-induced Pd-catalyzed one-pot three-component alkyl-carbamoylation and cyanation of alkenes was developed. This general transformation, which proceeds via the in situ formation of a reactive ketenimine intermediate, allows for a rapid construction of a broad range of valuable amides and nitriles from readily available alkenes, alkyl iodides, and isocyanides. An efficient synthesis of tetrazole and amidine via this approach was also demonstrated.
- Jia, Xiangqing,Zhang, Ziyan,Gevorgyan, Vladimir
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p. 13217 - 13222
(2021/11/01)
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- Arylboronic Acid Catalyzed C-Alkylation and Allylation Reactions Using Benzylic Alcohols
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The arylboronic acid catalyzed dehydrative C-alkylation of 1,3-diketones and 1,3-ketoesters using secondary benzylic alcohols as the electrophile is reported, forming new C-C bonds (19 examples, up to 98% yield) with the release of water as the only byproduct. The process is also applicable to the allylation of benzylic alcohols using allyltrimethylsilane as the nucleophile (12 examples, up to 96% yield).
- Estopi?á-Durán, Susana,McLean, Euan B.,Donnelly, Liam J.,Hockin, Bryony M.,Taylor, James E.
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supporting information
p. 7547 - 7551
(2020/10/09)
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- METHOD FOR PRODUCING ALLYLSILANE COMPOUND UTILIZING PALLADIUM NANOPARTICLE CATALYST
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PROBLEM TO BE SOLVED: To provide a method for efficiently producing an allylsilane compound from a substrate being inexpensive and capable of being easily handled in one step without using a large amount of a metal catalyst. SOLUTION: The method for producing an allylsilane compound represented by formula (C) includes a reaction step of reacting an allyl alcohol compound represented by formula (A) and a disilane compound represented by formula (B) in the presence of a palladium nanoparticle catalyst having a coordinating organic compound coordinated to the surface of a palladium nanoparticle and a co-catalyst. (In formulae (A) to (C), R1 to R3 each independently represent a hydrogen atom, a 1-20C aliphatic hydrocarbon group, a 6-20C aromatic hydrocarbon group or a 3-20C aromatic heterocyclic group; R4 and R5 each independently represent a hydrogen atom, 1-20C aliphatic hydrocarbon group, a 6-20C aromatic hydrocarbon group or a 3-20C aromatic heterocyclic group; and R6 to R8 each independently represent a hydrogen atom, a halogen atom, a 1-20C aliphatic hydrocarbon group or a 6-20C aromatic hydrocarbon group.) SELECTED DRAWING: None COPYRIGHT: (C)2020,JPOandINPIT
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Paragraph 0074-0078; 0086-0088
(2020/11/24)
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- Energy Transfer from CdS QDs to a Photogenerated Pd Complex Enhances the Rate and Selectivity of a Pd-Photocatalyzed Heck Reaction
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This Article describes the design of a colloidal quantum dot (QD) photosensitizer for the Pd-photocatalyzed Heck coupling of styrene and iodocyclohexane to form 2-cyclohexylstyrene. In the presence of 0.05 mol % CdS QDs, which have an emission spectrum that overlaps the absorption spectrum of a key Pd(II)alkyl iodide intermediate, the reaction proceeds with 82% yield for the Heck product at 0.5 mol % loading of Pd catalyst; no product forms at this loading without a sensitizer. A radical trapping experiment and steady-state and transient optical spectroscopies indicate that the QDs transfer energy to a Pd(II)alkyl iodide intermediate, pushing the reaction toward a Pd(I) alkyl radical species that leads to the Heck coupled product, and suppressing undesired β-hydride elimination directly from the Pd(II)alkyl iodide. Functionalization of the surfaces of the QDs with isonicotinic acid increases the rate constant of this reaction by a factor of 2.4 by colocalizing the QD and the Pd-complex. The modularity and tunability of the QD core and surface make it a convenient and effective chromophore for this alternative mode of cooperative photocatalysis.
- Zhang, Zhengyi,Rogers, Cameron R.,Weiss, Emily A.
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supporting information
p. 495 - 501
(2020/01/03)
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- Regioselectivity of Stoichiometric Metathesis of Vinylsilanes with Second-Generation Grubbs Catalyst: A Combined DFT and Experimental Study
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The regioselectivity of metathesis reactions of trisubstituted vinylsilanes H2C=CHSiR3 (SiR3 = SiCl3, SiCl2Me, SiClMe2, SiMe3, Si(OEt)3) with the second-generation rut
- ?liwa, Pawe?,Kurleto, Kamil,Handzlik, Jaros?aw,Rogalski, Szymon,Zak, Patrycja,Wyrzykiewicz, Bozena,Pietraszuk, Cezary
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supporting information
p. 621 - 628
(2016/03/25)
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- Palladium-Catalyzed Oxidative Silylation of Simple Olefins To Give Allylsilanes Using Hexamethyldisilane and Molecular Oxygen as the Sole Oxidant
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A Pd-catalyzed oxidative silylation of simple olefins with hexamethyldisilane to give allylsilanes has been achieved using molecular oxygen as the sole oxidant. The reaction provides a useful protocol to access synthetically useful allylsilanes from easil
- Nakai, Syunji,Matsui, Masaki,Shimizu, Yosuke,Adachi, Yurina,Obora, Yasushi
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p. 7317 - 7320
(2015/07/28)
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- Palladium-catalyzed C(sp 3)-C(sp 2) cross-coupling of (trimethylsilyl)methyllithium with (hetero)aryl halides
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The palladium-catalyzed direct cross-coupling of a range of organic chlorides and bromides with the bifunctional C(sp3)-(trimethylsilyl)methyllithium reagent is reported. The use of Pd-PEPPSI-IPent as the catalyst allows for the preparation of structurally diverse and synthetically versatile benzyl- and allylsilanes in high yields under mild conditions (room temperature) with short reaction times.
- Heijnen, Dorus,Hornillos, Valentín,Corbet, Brian P.,Giannerini, Massimo,Feringa, Ben L.
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supporting information
p. 2262 - 2265
(2015/05/13)
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- Catalysis and chemodivergence in the interrupted, formal homo-nazarov cyclization using allylsilanes
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A chemodivergent, Lewis acid catalyzed allylsilane interrupted formal homo-Nazarov cyclization is disclosed. With catalytic amounts of SnCl4 and in the presence of allyltrimethylsilane, a formal Hosomi-Sakurai-type allylation of the oxyallyl cation intermediate is observed. A variety of functionalized donor-acceptor cyclopropanes and allylsilanes were shown to be amenable to the reaction transformation and the allyl products were formed in up to 92% yield. Under dilute reaction conditions with stoichiometric SnCl4 and at reduced temperatures, an unusual formal [3 + 2]-cycloaddition between the allylsilane and the oxyallyl cation occurred to give hexahydrobenzofuran products in up to 69% yield.
- Shenje, Raynold,Williams, Corey W.,Francois, Katherine M.,France, Stefan
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supporting information
p. 6468 - 6471
(2015/02/05)
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- Mechanistic investigation of the palladium-catalyzed synthesis of allylic silanes and boronates from allylic alcohols
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The mechanism of the palladium-catalyzed synthesis of allylic silanes and boronates from allylic alcohols was investigated. 1H, 29Si, 19F, and 11B NMR spectroscopy was used to reveal key intermediates and byprod
- Larsson, Johanna M.,Szabó, Kálmán J.
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supporting information
p. 443 - 455
(2013/02/25)
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- Rhodium(II)-catalyzed stereoselective synthesis of allylsilanes
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The rhodium-catalyzed decomposition of 2-(triisopropylsilyl)ethyl aryl- and vinyldiazoacetates results in the stereoselective formation of Z-allylsilanes. The transformation is considered to proceed by silyl-directed intramolecular C-H functionalization to form a β-lactone intermediate followed by a silyl-activated extrusion of carbon dioxide.
- Guptill, David M.,Cohen, Carolyn M.,Davies, Huw M. L.
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p. 6120 - 6123
(2014/01/17)
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- Cobalt-catalyzed trimethylsilylmethylmagnesium-promoted radical alkenylation of alkyl halides: A complement to the Heck reaction
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A cobalt complex, [CoCl2(dpph)] (DPPH = [1,6- bis(diphenylphosphino)hexane]), catalyzes an intermolecular styrylation reaction of alkyl halides in the presence of Me3SiCH2MgCl in ether to yield β-alkylstyrenes. A variety of alkyl halides including alkyl chlorides can participate in the styrylation. A radical mechanism is strongly suggested for the styrylation reaction. The sequential isomerization/styrylation reactions of cyclopropylmethyl bromide and 6-bromo-1-hexene provide evidence of the radical mechanism. Crystallographic and spectroscopic investigations on cobalt complexes reveal that the reaction would begin with single electron transfer from an electron-rich (diphosphine)bis(trimethylsilylmethyl)cobalt(II) complex followed by reductive elimination to yield 1,2-bis(trimethylsilyl)ethane and a (diphosphine)cobalt(I) complex. The combination of [CoCl 2(dppb)] (DPPB = [1,4-bis(diphenylphosphino)butane]) catalyst and Me3SiCH2-MgCl induces intramolecular Heck-type cyclization reactions of 6-halo-1-hexenes via a radical process. On the other hand, the intramolecular cyclization of the prenyl ether of 2-iodophenol would proceed in a fashion similar to the conventional palladium-catalyzed transformation. The nonradical oxidative addition of carbon(sp2)-halogen bonds to cobalt is separately verified by a cobalt-catalyzed cross-coupling reaction of alkenyl halides with Me3SiCH2MgCl with retention of configuration of the starting vinyl halides. The cobalt-catalyzed intermolecular radical styrylation reaction of alkyl halides is applied to stereoselective variants. Styrylations of 1-alkoxy-2-bromocyclopentane derivatives provide trans-1-alkoxy-2-styrylcyclopentane skeletons, one of which is optically pure.
- Affo, Walter,Ohmiya, Hirohisa,Fujioka, Takuma,Ikeda, Yousuke,Nakamura, Tomoaki,Yorimitsu, Hideki,Oshima, Koichiro,Imamura, Yuki,Mizuta, Tsutomu,Miyoshi, Katsuhiko
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p. 8068 - 8077
(2007/10/03)
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- Silicon-directed Bamford-Stevens Reaction of β-Trimethylsilyl N-Aziridinylimines
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The Me3Si group in β-trimethylsilyl N-aziridinylimines is able to direct the Bamford-Stevens reaction with or without rhodium acetate as catalyst to give allylic silanes as major or exclusive products.
- Sarkar, Tarun K.,Ghorai, Binay K.
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p. 1184 - 1185
(2007/10/02)
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- TRIS(2-METHYLPHENYL)PHOSPHORANE, A MODIFIED SEYFERTH-WITTIG REAGENT FOR THE STEREOSELECTIVE SYNTHESES OF Z-ALLYLTRIMETHYLSILANES
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The Wittig reactions between title β-silylphosphorus ylide and aliphatic aldehydes give selectively Z-allyltrimethylsilanes with minimal formation of vinylation products.
- Iio, Hideo,Ishii, Masahiro,Tsukamoto, Masamitsu,Tokoroyama, Takashi
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p. 5965 - 5968
(2007/10/02)
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- Electrochemical Synthesis of Organosilicon Compounds
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Electrochemical reduction of allyl, aryl, and vinyl halides in the presence of a silylating agent (Me3SiCl, HMe2SiCl, and PhMe2SiCl) in a solution of tetraethylammonium tosylate in dimethylformamide (DMF) gave the corresponding organosilicon compounds.The regioselectivity of the reaction of allylic halides depends on the nature of the silylating agent.Trimethylsilyl and dimethylphenylsilyl groups were introduced to the less substituted end of the allyl group, whereas the dimethylsilyl group was introduced to both ends of the allyl group.High chemoselectivity of the present approach was demonstrated by selectivity monosilylations of p-bromoiodobenzene and p-bromocinnamyl chloride to obtain (p-bromophenyl)trimethylsilane and (p-bromocinnamyl)trimethylsilane, respectively.A mechanism involving a carbanion intermediate is suggested.
- Yoshida, Jun-ichi,Muraki, Katsuhiko,Funahashi, Hirokatsu,Kawabata, Nariyoshi
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p. 3996 - 4000
(2007/10/02)
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- A FACILE SYNTHESIS OF HOMOALLYL ETHERS. THE REACTION OF ACETALS WITH ALLYLTRIMETHYLSILANES PROMOTED BY TRITYL PERCHLORATE OR DIPHENYLBORYL TRIFLATE
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In the presence of a catalytic amount of trityl perchlorate or diphenylboryl triflate, acetals react smoothly with allyltrimethylsilanes to give the corresponding homoallyl ethers in good yields with good regio- and stereoselectivities.
- Mukaiyama, Teruaki,Nagaoka, Hitoshi,Murakami, Masahiro,Ohshima, Masahiro
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p. 977 - 980
(2007/10/02)
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- PRACTICAL SYNTHESES OF ALLYLSILANES FROM 1-BENZENESULFONYL-2-TRIMETHYLSILYLETHANE
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The methanesulfonates of the adducts of aldehydes and ketones with 1-(1-benzenesulfonyl-2-trimethylsilyl)ethyllithium are converted by sodium-amalgam to allylsilanes.
- Hsiao, C-N.,Shechter, H.
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p. 1963 - 1966
(2007/10/02)
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