56633-16-0Relevant articles and documents
METHOD OF PREPARING SILANOLS WITH SELECTIVE CYTOCHROME P450 VARIANTS AND RELATED COMPOUNDS AND COMPOSITIONS
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Paragraph 00150-00152, (2021/08/27)
This disclosure provides a method of preparing a silanol-functional organosilicon compound with a cytochrome P450 variant that facilitates the oxidization of a silyl hydride group to a silanol group in the presence of oxygen. The method includes combining the cytochrome P450 variant and an organosilicon compound having at least one silicon-bonded hydrogen atom to give a reaction mixture and exposing the reaction mixture to oxygen to oxidize the organosilicon compound, thereby preparing the silanol-functional organosilicon compound. Cytochrome P450 variants suitable for use in the method are also disclosed, along with methods for engineering and optimizing the same. Nucleic acids encoding the cytochrome P450 variants and compositions, expression vectors, and host cells including the same are also disclosed.
Metal-free hydrogen evolution cross-coupling enabled by synergistic photoredox and polarity reversal catalysis
Cao, Jilei,Lu, Kanghui,Ma, Lishuang,Yang, Xiaona,Zhou, Rong
supporting information, p. 8988 - 8994 (2021/11/23)
A synergistic combination of photoredox and polarity reversal catalysis enabled a hydrogen evolution cross-coupling of silanes with H2O, alcohols, phenols, and silanols, which afforded the corresponding silanols, monosilyl ethers, and disilyl ethers, respectively, in moderate to excellent yields. The dehydrogenative cross-coupling of Si-H and O-H proceeded smoothly with broad substrate scope and good functional group compatibility in the presence of only an organophotocatalyst 4-CzIPN and a thiol HAT catalyst, without the requirement of any metals, external oxidants and proton reductants, which is distinct from the previously reported photocatalytic hydrogen evolution cross-coupling reactions where a proton reduction cocatalyst such as a cobalt complex is generally required. Mechanistically, a silyl cation intermediate is generated to facilitate the cross-coupling reaction, which therefore represents an unprecedented approach for the generation of silyl cationviavisible-light photoredox catalysis.
Photocatalyzed cross-dehydrogenative coupling of silanes with alcohols and water
Lv, Haiping,Laishram, Ronibala Devi,Chen, Jingchao,Khan, Ruhima,Zhu, Yuanbin,Wu, Shiyuan,Zhang, Jianqiang,Liu, Xingyuan,Fan, Baomin
supporting information, p. 3660 - 3663 (2021/04/16)
An efficient method for the dehydrogenative coupling of silanes with alcohols under photocatalysis was developed. The reaction proceeded in the presence of Ru(bpy)3Cl2(0.5 mol%) under visible light irradiation in acetonitrile at room temperature. The developed methodology was also applicable for the synthesis of silanols using water as a coupling partner.
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.
Highly Selective Hydroxylation and Alkoxylation of Silanes: One-Pot Silane Oxidation and Reduction of Aldehydes/Ketones
Luo, Nianhua,Liao, Jianhua,Ouyang, Lu,Wen, Huiling,Zhong, Yuhong,Liu, Jitian,Tang, Weiping,Luo, Renshi
, p. 165 - 171 (2020/01/21)
An efficient chemoselective iridium-catalyzed method for the hydroxylation and alkoxylation of organosilanes to generate hydrogen gas and silanols or silyl ethers was developed. A variety of sterically hindered silanes with alkyl, aryl, and ether groups were tolerated. Furthermore, this atom-economical catalytic protocol can be used for the synthesis of silanediols and silanetriols. A one-pot silane oxidation and chemoselective reduction of aldehydes/ketones was also realized.
Selective Enzymatic Oxidation of Silanes to Silanols
Arnold, Frances H.,B?hr, Susanne,Brinkmann-Chen, Sabine,Garcia-Borràs, Marc,Houk, K. N.,Katsoulis, Dimitris E.,Roberts, John M.
supporting information, p. 15507 - 15511 (2020/05/05)
Compared to the biological world's rich chemistry for functionalizing carbon, enzymatic transformations of the heavier homologue silicon are rare. We report that a wild-type cytochrome P450 monooxygenase (P450BM3 from Bacillus megaterium, CYP102A1) has promiscuous activity for oxidation of hydrosilanes to give silanols. Directed evolution was applied to enhance this non-native activity and create a highly efficient catalyst for selective silane oxidation under mild conditions with oxygen as the terminal oxidant. The evolved enzyme leaves C?H bonds present in the silane substrates untouched, and this biotransformation does not lead to disiloxane formation, a common problem in silanol syntheses. Computational studies reveal that catalysis proceeds through hydrogen atom abstraction followed by radical rebound, as observed in the native C?H hydroxylation mechanism of the P450 enzyme. This enzymatic silane oxidation extends nature's impressive catalytic repertoire.
Synthesis of a Gold–Metal Oxide Core–Satellite Nanostructure for In Situ SERS Study of CuO-Catalyzed Photooxidation
Bai, Lu,Fan, Chenghao,Hu, Yanfang,Li, Yonglong,Liu, Jun,Shi, Faxing,Xie, Wei,Yang, Ling,Zhang, Kaifu,Zhao, Yaran
, p. 18003 - 18009 (2020/08/21)
This work reports on an assembling–calcining method for preparing gold–metal oxide core–satellite nanostructures, which enable surface-enhanced Raman spectroscopic detection of chemical reactions on metal oxide nanoparticles. By using the nanostructure, we study the photooxidation of Si?H catalyzed by CuO nanoparticles. As evidenced by the in situ spectroscopic results, oxygen vacancies of CuO are found to be very active sites for oxygen activation, and hydroxide radicals (*OH) adsorbed at the catalytic sites are likely to be the reactive intermediates that trigger the conversion from silanes into the corresponding silanols. According to our finding, oxygen vacancy-rich CuO catalysts are confirmed to be of both high activity and selectivity in photooxidation of various silanes.
Selective Manganese-Catalyzed Oxidation of Hydrosilanes to Silanols under Neutral Reaction Conditions
Wang, Kaikai,Zhou, Jimei,Jiang, Yuting,Zhang, Miaomiao,Wang, Chao,Xue, Dong,Tang, Weijun,Sun, Huamin,Xiao, Jianliang,Li, Chaoqun
supporting information, p. 6380 - 6384 (2019/05/06)
The first manganese-catalyzed oxidation of organosilanes to silanols with H2O2 under neutral reaction conditions has been accomplished. A variety of organosilanes with alkyl, aryl, alknyl, and heterocyclic substituents were tolerated, as well as sterically hindered organosilanes. The oxidation appears to proceed by a concerted process involving a manganese hydroperoxide species. Featuring mild reaction conditions, fast oxidation, and no waste byproducts, the protocol allows a low-cost, eco-benign synthesis of both silanols and silanediols.
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.
Organosilane oxidation with a half million turnover number using fibrous nanosilica supported ultrasmall nanoparticles and pseudo-single atoms of gold
Dhiman, Mahak,Chalke, Bhagyashree,Polshettiwar, Vivek
supporting information, p. 1935 - 1940 (2017/02/10)
The combination of ultrasmall nanoparticles and pseudo-single atoms of gold (Au) and fibrous nanosilica (KCC-1) functionalized with 3-aminopropyltriethoxysilane (APTS) enabled the design of KCC-1-APTS/Au nanocatalysts with very high turnover numbers (TONs). KCC-1-APTS/Au catalysed the oxidation of organosilanes to silanols, with a TON of approximately half a million (591000 for dimethylphenyl silane as a model substrate). Additionally, the figure-of-merit (FOM), which provides an integrated view of the rate of the reaction, the energy required, the reaction scale and the recyclability of the catalysts, was 633 mmol h-1 K-1. KCC-1-APTS/Au also catalysed two additional challenging reactions, the alcoholysis of silane and the hydrosilylation of aldehydes, with very high TONs. These characteristics make KCC-1-APTS/Au a versatile nanocatalyst.
