1842-25-7Relevant academic research and scientific papers
Divergent Synthesis of Vinyl-, Benzyl-, and Borylsilanes: Aryl to Alkyl 1,5-Palladium Migration/Coupling Sequences
Han, Jie-Lian,Ju, Cheng-Wei,Qin, Ying,Zhao, Dongbing
supporting information, p. 6555 - 6560 (2020/03/03)
Organosilicon compounds have been extensively utilized both in industry and academia. Studies on the syntheses of diverse organosilanes is highly appealing. Through-space metal/hydrogen shifts allow functionalization of C?H bonds at a remote site, which are otherwise difficult to achieve. However, until now, an aryl to alkyl 1,5-palladium migration process seems to have not been presented. Reported herein is the remote olefination, arylation, and borylation of a methyl group on silicon to access diverse vinyl-, benzyl-, and borylsilanes, constituting a unique C(sp3)?H transformation based on a 1,5-palladium migration process.
C(sp3)-H Bond Arylation and Amidation of Si-Bound Methyl Group via Directing Group Strategy
Han, Jie-Lian,Qin, Ying,Zhao, Dongbing
, p. 6020 - 6026 (2019/06/25)
Silylmethyl functionalization provides a general and efficient access to diverse organosilanes. The traditional methods for silylmethyl functionalization often involved silylmethylmetals or silylmethylhalides. In recent years, a C-H activation strategy has become one of the most attractive alternatives in organic synthesis. We envisioned that the attachment of a coordinating group at silicon of methylsilanes provides the opportunity to modify the silylmethyl group via directed C-H bond functionalization. However, despite employment of silicon tethers bearing a directing group (DG) for C(sp2)-H functionalization has been well established due to the fact that the silicon tethers are easily installable and removable/modifiable, applying this concept toward C(sp3)-H functionalization remains underdeveloped. Herein, we successfully develop IrIII/RhIII-catalyzed C-H bond arylation/amidation of silyl methyl group by using directing group strategy, which constitutes the most powerful access to benzylsilanes and amino-substituted silanes. Moreover, we demonstrated that the pyridine directing group on silicon atom can be easily removed, and the starting materials can also be efficiently recovered, which are different from those of pyridine-directed C-H functionalization of C-bound methyl group.
On the configurational stability of chiral heteroatom-substituted [D 1]Methylpalladium complexes as intermediates of stille and suzuki-miyaura cross-coupling reactions
Malova Krizkova, Petra,Hammerschmidt, Friedrich
supporting information, p. 5143 - 5148 (2013/11/06)
Enantiomerically pure (S)-tributylstannyl[D1]methanol and (R)- and (S)-tributylstannyl[D1]methyl benzoates were Stille-coupled with bromobenzene and benzoyl chloride in 1,4-dioxane and toluene using [(Ph 3P)4Pd] or [(Ph3P)2PdCl2] either alone or in combination with CuCN as cocatalyst at temperatures up to 80 °C. The products were found to be enantiomerically pure. (R)- and (S)-N-(tributylstannyl[D1]methyl)phthalimides gave enantiomerically pure products with benzoyl chloride, but with bromobenzene protected phenyl[D1]methylamines gave products of only 52-69 % ee depending on the solvent used. Tributyl(thio[D1]methyl)stannanes could not be Stille-coupled with benzoyl chloride or with bromobenzene. Similarly, dimethyl phenyl[D1]methylboronate underwent a Suzuki-Miyaura coupling with bromobenzene to give phenyl[D1]methylsilane with 99 % ee. All couplings followed a retentive course and, except in one case, the intermediate [XCHDPdLn] complexes were found to be microscopically configurationally stable. Stille coupling of enantiomerically pure tributylstannyl[D1]methanol, its benzoate, and the N-(tributylstannyl[D1]methyl)phthalimide with bromobenzene and benzoyl chloride furnished products containing a chiral XCHD group. Overall net retention of configuration was found in all cases.
Rearrangements of Organosilicon Compounds Using Organoaluminum Reagents. Conversion of Phenyl- and Alkenyl(chloromethyl)silanes to Benzyl- and Allylsilanes
Hudrlik, Paul F.,Abdallah, Yousef M.,Kulkarni, Ashok K.,Hudrlik, Anne M.
, p. 6552 - 6556 (2007/10/02)
Various (chloromethyl)silanes undergo Wagner-Meerwein-type rearrangements using a catalytic amount of EtAlCl2 in dichloromethane.The resulting chlorosilanes have been converted to alkyl(or aryl)silanes with RMgX and/or to fluorosilanes with NH4HF2.In this way phenyl-, alkenyl-, and allyl(chloromethyl)silanes were converted to benzyl-, allyl-, and homoallylsilanes, respectively.Attempted rearrangements of methyl-, alkynyl-, and furyl(chloromethyl)silanes under these conditions were not successful.
Gas-Phase Reactions of Anions with Substituted Silanes
DePuy, C. H.,Bierbaum, Veronica M.,Flippin, L. A.,Grabowski, Josef J.,King, Gary K.,et al.
, p. 5012 - 5015 (2007/10/02)
The gas-phase reactions of fluoride, amide, hydroxide, and methoxide ions with a variety of substituted silanes have been studied by the flowing afterglow technique.Fluoride reacts readily with trimethylsilyl derivatives to displace benzyl, alkenyl, and alkynyl anions.These reactions have also been used to generate specific structural isomers (CH3CC- and CH2C=C=CH-).Anions more basic than phenide ion cannot be produced in this manner, and their parent trimethylsilanes interact with fluoride by more complex mechanisms.Amide, hydroxide, and methoxide ions react with substituted trimethylsilanes by both displacement and proton abstraction whenever an acidic hydrogen is present; in the absence of displaceable groups and acidic hydrogen, the reactions of amide, hydroxide, and methoxide parallel those of fluoride ion.
