7604-85-5Relevant academic research and scientific papers
Synergistic Catalysis by Br?nsted Acid/Carbodicarbene Mimicking Frustrated Lewis Pair-Like Reactivity
Bai, Yuna,Chan, Yi-Chen,Chen, Hsing-Yin,Chen, Hsuan-Ying,Chen, Wen-Ching,Li, Chen-Yu,Ong, Tiow-Gan,Tseng, Mei-Chun,Wu, Ying-Yann,Yap, Glenn P. A.,Zhao, Lili
supporting information, p. 19949 - 19956 (2021/08/03)
Carbodicarbene (CDC), unique carbenic entities bearing two lone pairs of electrons are well-known for their strong Lewis basicity. We demonstrate herein, upon introducing a weak Br?nsted acid benzyl alcohol (BnOH) as a co-modulator, CDC is remolded into a Frustrated Lewis Pair (FLP)-like reactivity. DFT calculation and experimental evidence show BnOH loosely interacting with the binding pocket of CDC via H-bonding and π-π stacking. Four distinct reactions in nature were deployed to demonstrate the viability of proof-of-concept as synergistic FLP/Modulator (CDC/BnOH), demonstrating enhanced catalytic reactivity in cyclotrimerization of isocyanate, polymerization process for L-lactide (LA), methyl methacrylate (MMA) and dehydrosilylation of alcohols. Importantly, the catalytic reactivity of carbodicarbene is uniquely distinct from conventional NHC which relies on only single chemical feature of nucleophilicity. This finding also provides a new spin in diversifying FLP reactivity with co-modulator or co-catalyst.
Synthesis and Applications of Silyl 2-Methylprop-2-ene-1-sulfinates in Preparative Silylation and GC-Derivatization Reactions of Polyols and Carbohydrates
Markovic, Dean,Tchawou, Wandji Augustin,Novosjolova, Irina,Laclef, Sylvain,Stepanovs, Dmitrijs,Turks, Maris,Vogel, Pierre
, p. 4196 - 4205 (2016/03/16)
Trimethylsilyl, triethylsilyl, tert-butyldimethylsilyl, and triisopropylsilyl 2-methylprop-2-ene-1-sulfinates were prepared through (CuOTf)2C6H6-catalyzed sila-ene reactions of the corresponding methallylsilanes with SO2 at 50 °C. Sterically hindered, epimerizable, and base-sensitive alcohols gave the corresponding silyl ethers in high yields and purities at room temperature and under neutral conditions. As the byproducts of the silylation reaction (SO2+isobutylene) are volatile, the workup was simplified to solvent evaporation. The developed method can be employed for the chemo- and regioselective semiprotection of polyols and glycosides and for the silylation of unstable aldols. The high reactivity of the developed reagents is shown by the synthesis of sterically hindered per-O-tert-butyldimethylsilyl-α-d-glucopyranose, the X-ray crystallographic analysis of which is the first for a per-O-silylated hexopyranose. The per-O-silylation of polyols, hydroxy carboxylic acids, and carbohydrates with trimethylsilyl 2-methylprop-2-ene-1-sulfinate was coupled with the GC analysis of nonvolatile polyhydroxy compounds both qualitatively and quantitatively. Regio- and chemoselective silylation of polyols and carbohydrates has been achieved by employing silyl sulfinates (see the picture; TBS=tert-butyldimethylsilyl, TES=triethylsilyl, TIPS=triisopropylsilyl, TMS=trimethylsilyl). The silylation reactions proceed in high yield because the reactions are mild and fast and produce only volatile byproducts. Furthermore, the silyl sulfinates are used as new derivatization reagents for the GC analysis of nonvolatile polyhydroxy compounds.
Activation of silanes by Grubbs' carbene complex Cl2(PCy3)2Ru=CHPh: Dehydrogenative condensation of alcohols and hydrosilylation of carbonyls
Maifeld, Sarah V,Miller, Reagan L,Lee, Daesung
, p. 6363 - 6366 (2007/10/03)
This manuscript describes two catalytic methods for silyl ether synthesis using Grubbs' catalyst Cl2(PCy3)2Ru=CHPh. Silyl ethers are obtained from the reaction of a variety of silanes with alcohols by dehydrogenative conde
Rhodium(II) Perfluorobutyrate Catalyzed Silane Alcoholysis. A Highly Selective Route to Silyl Ethers
Doyle, Michael P.,High, Kenneth G.,Bagheri, Vahid,Pieters, Roland J.,Lewis, Patricia J.,Pearson, Matthew M.
, p. 6082 - 6086 (2007/10/02)
Rhodium(II) perfluorobutyrate, Rh2(pfb)4, is an effective catalyst for the alcoholysis of trialkylsilanes at room temperature.Primary alcohols react with triethylsilane approximately 5 times faster than do secondary alcohols, and tertiary alcohols are virtually inert.Enhanced selectivity is achieved with tert-butyldimethylsilane.Hydrosilylation of olefinic alcohols is relatively unimportant even with terminal alkenes, but Rh2(pfb)4 does promote hydrogenation of 3-phenyl-2-propen-1-ol.Selected diols have been silylated with complete regioselectivity in Rh2(pfb)4-catalyzed reactions with either triethylsilane or tert-butyldimethylsilane.Methanolysis of (S)-(-)-1-naphthylphenylmethylsilane occurs with nearly complete inversion of configuration at silicon, and spectral analysis of the catalytic reaction suggests a mechanism for silane alcoholysis in which the rhodium(II) catalyst coordinates with the silicon hydride to activate silicon for backside nucleophilic attack by the alcohol.
