7443-52-9Relevant articles and documents
Transformation of organic compounds in the presence of metal complexes. IV. Hydrosilylation of 2- and 4-alkylcyclohexanones on rhodium(I) complexes
Felfoeldi, K.,Kapocsi, I.,Bartok, M.
, p. 411 - 416 (1989)
The hydrosilylation of 2- and 4-alkylcyclohexanones with Ph2SiH2 was studied under various conditions.The isomeric distribution of the resulting alcohols, i.e. the stereochemistry of the hydrosilylation, is influenced by the position and size of the alkyl groups, the catalyst concentration, the reaction temperature, and the types of ligand attached.
Addition Compounds of Alkali Metal Hydrides. 27. A General Method for Preparation of the Potassium 9-Alkoxy-9-boratabicyclononanes. A New Class of Stereoselective Reducing Agents
Brown, Herbert C.,Cha, Jin Soon,Nazer, Behrooz,Brown, Charles A.
, p. 549 - 553 (1985)
The reaction in tetrahydrofuran of potassium hydride with representative B-alkoxy-9-borabicyclononanes (B-OR-9-BBN) containing alkoxy groups with increasing steric requirements was examined in detail to establish the generality of this synthesis of the corresponding potassium 9-alkoxy-9-boratabicyclononanes (K9-OR-9-BBNH) and the stereoselectivities of these new reagents for the reduction of cyclic ketones.For R = Me and n-Bu, the reactions with potassium hydride are very fast, almost instantaneous, even at 0 deg C.However, the products are unstable and rapidly undergo redistribution, even in the presence of excess potassium hydride.Moderately hindered alkoxy derivatives, R = 2-Pr and 2-Bu, react somewhat slower (1 h at 0 deg C and 25 deg C, respectively) and the products are stable to redistribution.More hindered alkoxy derivatives, R = t-Bu, t-Am, Thx, require 24 h at 25 deg C.Even more hindered alkoxy groups, R = 3-ethyl-3-pentyl and 2,4-dimethyl-2-pentyl, require even longer reaction times and higher temperatures.All reagents show high stereoselectivities in the reduction of cyclic ketones, with the stereoselectivities generally increasing with increasing steric requirements of the alkoxy substituent.The thexyl derivative appears especially favorable, with the byproducts of the reaction readily removed from the reaction mixture.
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Dauben,Bozak
, p. 1596,1597 (1959)
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Cobalt-Nanoparticles Catalyzed Efficient and Selective Hydrogenation of Aromatic Hydrocarbons
Murugesan, Kathiravan,Senthamarai, Thirusangumurugan,Alshammari, Ahmad S.,Altamimi, Rashid M.,Kreyenschulte, Carsten,Pohl, Marga-Martina,Lund, Henrik,Jagadeesh, Rajenahally V.,Beller, Matthias
, p. 8581 - 8591 (2019/09/12)
The development of inexpensive and practical catalysts for arene hydrogenations is key for future valorizations of this general feedstock. Here, we report the development of cobalt nanoparticles supported on silica as selective and general catalysts for such reactions. The specific nanoparticles were prepared by assembling cobalt-pyromellitic acid-piperazine coordination polymer on commercial silica and subsequent pyrolysis. Applying the optimal nanocatalyst, industrial bulk, substituted, and functionalized arenes as well as polycyclic aromatic hydrocarbons are selectively hydrogenated to obtain cyclohexane-based compounds under industrially viable and scalable conditions. The applicability of this hydrogenation methodology is presented for the storage of H2 in liquid organic hydrogen carriers.
(Poly)cationic λ3-Iodane-Mediated Oxidative Ring Expansion of Secondary Alcohols
Walters, Jennifer C.,Tierno, Anthony F.,Dubin, Aimee H.,Wengryniuk, Sarah E.
supporting information, p. 1460 - 1464 (2018/04/06)
Herein, a simplified approach to the synthesis of medium-ring ethers through the electrophilic activation of secondary alcohols with (poly)cationic λ3-iodanes (N-HVIs) is reported. Excellent levels of selectivity are achieved for C–O bond migration over established α-elimination pathways, enabled by the unique reactivity of a novel 2-OMe-pyridine-ligated N-HVI. The resulting hexafluoroisopropanol (HFIP) acetals are readily derivatized with a range of nucleophiles, providing a versatile functional handle for subsequent manipulations. The utility of this methodology for late-stage natural product derivatization was also demonstrated, providing a new tool for diversity-oriented synthesis and complexity-to-diversity (CTD) efforts. Preliminary mechanistic investigations reveal a strong effect of alcohol conformation on the reactive pathway, thus providing a predictive power in the application of this approach to complex molecule synthesis.
Asymmetric Induction via a Helically Chiral Anion: Enantioselective Pentacarboxycyclopentadiene Br?nsted Acid-Catalyzed Inverse-Electron-Demand Diels-Alder Cycloaddition of Oxocarbenium Ions
Gheewala, Chirag D.,Hirschi, Jennifer S.,Lee, Wai-Hang,Paley, Daniel W.,Vetticatt, Mathew J.,Lambert, Tristan H.
supporting information, p. 3523 - 3527 (2018/03/21)
An enantioselective catalytic inverse-electron-demand Diels-Alder reaction of salicylaldehyde acetal-derived oxocarbenium ions and vinyl ethers to generate 2,4-dioxychromanes is described. Chiral pentacarboxycyclopentadiene (PCCP) acids are found to be effective for a variety of substrates. Computational and X-ray crystallographic analyses support the unique hypothesis that an anion with point-chirality-induced helical chirality dictates the absolute sense of stereochemistry in this reaction.
