Aluminium Triflate [Al(OTf)<sub>3</sub>] as a Recyclable Catalyst for the Conversion of α-Hydroxyphosphonates, Alcohols and Phenols to Their Corresponding O-Silylated Products with Hexamethyldisilazane (HMDS)
Al(OTf)3 as a recyclable catalyst conducts the efficient conversion of various types of α-hydroxyphosphonates to their corresponding α-trimethysilyloxyphosphonates with HMDS in the absence of solvent at room temperature. The general applicability of the catalyst under solvent-free conditions is demonstrated by applying it for the successful silylation of alcohols and phenols with HMDS in high yields.
Novel and Highly Effective Method for the Trimethylsilylation of Alcohols and Phenols with Hexamethyldisilazane (HMDS), Catalyzed by I<sub>2</sub>Generated<i>in situ</i>Using Fe(NO<sub>3</sub>)<sub>3</sub>⋅9 H<sub>2</sub>O/NaI under Heterogeneous and Neutral Conditions
作者:Ardeshir Khazaei、Sadegh Rahmati、Amin Rostami
DOI:10.1002/hlca.200900002
日期:2009.7
Structurally diverse alcohols and phenols were trimethylsilylated in a clean and efficient reaction with hexamethyldisilazane (HMDS) based on the use of I2 generated in situ from Fe(NO3)3⋅9H2O/NaI. The reaction occurs very rapid in good‐to‐high yield in CH2Cl2 at room temperature, and the use of toxic and corrosive molecular I2 is avoided.
结构不同的醇和酚是在用六甲基二硅烷(HMDS)清洁和有效的反应基于使用的我三甲基甲硅烷2产生原位选自Fe(NO 3)3 ⋅9ħ 2 O /碘化钠。在室温下,该反应在CH 2 Cl 2中以高至高收率非常迅速地发生,并且避免使用有毒和腐蚀性的分子I 2。
Iron–Nickel Dual-Catalysis: A New Engine for Olefin Functionalization and the Formation of Quaternary Centers
作者:Samantha A. Green、Suhelen Vásquez-Céspedes、Ryan A. Shenvi
DOI:10.1021/jacs.8b05868
日期:2018.9.12
electron-deficient arenes, including Lewis basic heterocycles. Here we report a highly Markovnikov-selective, dual-catalytic olefin hydroarylation that tolerates arenes and heteroarenes of any electronic character. Hydrogen atom transfer controls the formation of branched products and arene halogenation specifies attachment points on the aromatic ring. Mono-, di-, tri-, and tetra-substituted alkenes yield Markovnikov
The selective cleavage of tetrahydropyranyl (THP), methoxymethyl (MOM), 1-ethoxyethyl (EE), 1-methyl-1-methoxyethyl (MME) and trimethylsilyl (TMS) ether groups with silica-aluminagels prepared by the sol-gel method has been investigated. The deprotection rate follows the order: TMS > MME ⪢ EE > THP ⪢ MOM. The selective deprotection of diol derivatives with mixed protecting groups was achieved efficiently
Structurally diverse alcohols and phenols were efficiently transformed into their corresponding trimethylsilyl ethers with hexamethyldisilazane (HMDS) in the presence of catalytic amounts of sulfamic acid (SA) at room temperature under both acetonitrile and solvent-free conditions. Deprotection of these trimethylsilyl ethers to their parent alcohols and phenols was also achieved using this catalyst in water at room temperature.