- Oxoammonium-Mediated Allylsilane–Ether Coupling Reaction
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A new C(sp3)?H functionalization reaction consisting of the oxidative α-allylation of allyl- and benzyl- methyl ethers has been developed. The C?C coupling could be carried out under mild conditions thanks to the use of cheap and green oxoammonium salts. The scope of the reaction was studied over 27 examples, considering the nature of the substituents on the two coupling partners.
- Carlet, Federica,Bertarini, Greta,Broggini, Gianluigi,Pradal, Alexandre,Poli, Giovanni
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supporting information
p. 2162 - 2168
(2021/04/02)
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- Regioselective Silylations of Propargyl and Allyl Pivalates through Ca-Promoted Reductive C(sp3)-O Bond Cleavage
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A practical protocol for the regioselective preparation of 3-phenylpropargylsilanes and 3-phenylallylsilanes in yields of 36-77 and 48-86%, respectively, from readily accessible 3-phenylpropargyl and 1-phenylallyl pivalates was developed through reductive C(sp3)-O bond cleavage. This method represents the first example of the direct application of vastly abundant calcium granules to a reductive coupling reaction. A broad range of propargylsilanes and allylsilanes are simply prepared using easy-to-handle pivalates and chlorotrimethylsilane under mild catalyst-free and additive-free conditions.
- Zhang, Tianyuan,Zheng, Suhua,Kobayashi, Taro,Maekawa, Hirofumi
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p. 7129 - 7133
(2021/09/18)
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- Nickel-Mediated Enantiospecific Silylation via Benzylic C-OMe Bond Cleavage
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Benzylic stereocenters are found in bioactive and drug molecules, as enantiopure benzylic alcohols have been used to build such a stereogenic center, but are limited to the construction of a C-C bond. Silylation of alkyl alcohols has the potential to build bioactive molecules and building blocks; however, the development of such a process is challenging and unknown. Herein, we describe an unprecedented AgF-assisted nickel catalysis in the enantiospecific silylation of benzylic ethers.
- Balakrishnan, Venkadesh,Murugesan, Vetrivelan,Chindan, Bincy,Rasappan, Ramesh
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p. 1333 - 1338
(2021/02/20)
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- Palladium-catalyzed allylic C-OH functionalization for efficient synthesis of functionalized allylsilanes
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A new method is described for palladium-catalyzed allylic silylation using allylic alcohols and disilanes as precursors. The reactions proceed smoothly under mild and neutral conditions, and this method is suitable for synthesis of regioand stereodefined allylsilanes. The presented silylation reaction can be easily extended to include synthesis of allylboronates by change of the dimetallic reagent. The presented synthetic procedure offers a broad platform for the selective synthesis of functionalized allyl metal reagents, which are useful precursors in advanced organic chemistry and natural product synthesis.
- Selander, Nicklas,Paasch, Jennifer R.,Szabo, Kalman J.
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supporting information; experimental part
p. 409 - 411
(2011/04/15)
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- Asymmetric Synthesis Catalyzed by Chiral Ferrocenylphosphine-Transition-Metal Complexes. 3. Preparation of Optically Active Allylsilanes by Palladium-Catalyzed Asymmetric Grignard Cross-Coupling
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Asymmetric cross-coupling of the - or -Grignard reagent with alkenyl bromides in the presence of a chiral ferrocenylphosphine-palladium complex, dichloroethylamine>palladium(II) (PdCl2), as a catalyst, gave optically active allylsilanes which contain an asymmetric carbon atom directly bonded to the silicon atom, e.g., (R)-3-phenyl-3-(trimethylsilyl)propene (3a) (95percent ee), (R,E)-1-phenyl-1-(trimethylsilyl)-2-butene (3b) (85percent ee), (R,Z)-3b (24percent ee), (R,E)-1,3-diphenyl-3- (trimethylsilyl)propene (3c) (95percent ee), (S,E)-1-phenyl-3-(trimethylsilyl)-1-butene (14c) (71percent ee), (S,Z)-14c (59percent ee), (S,E)-1-phenyl-3-(triethylsilyl)-1-butene (16c) (93percent ee), (S,E)-3-(triethylsilyl)-2-pentene (16b) (85percent ee), (S,E,E)-2-(dimethylphenylsilyl)-3,5-heptadiene (15d) (45percent ee), and 1-cyclopentene (21) (37percent ee).The configuration and enantiomeric purity of the allylsilanes were determined with the aid of stereoselective oxidative cleavage of the carbon-silicon bond in optically active alkylsilanes.
- Hayashi, Tamio,Konishi, Mitsuo,Okamoto, Yasuo,Kabeta, Keiji,Kumada, Makoto
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p. 3772 - 3781
(2007/10/02)
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