4484-57-5Relevant academic research and scientific papers
Bio-inspired asymmetric aldehyde arylations catalyzed by rhodium-cyclodextrin self-inclusion complexes
Asahi, Kaoru,Fujiwara, Shin-Ichi,Iwasaki, Takanori,Kambe, Nobuaki,Takahashi, Ryota,Tsuda, Susumu,Ueda, Ryoji,Yamauchi, Hiroki
supporting information, p. 801 - 807 (2022/02/03)
Transition-metal catalysts are powerful tools for carbon-carbon bond-forming reactions that are difficult to achieve using native enzymes. Enzymes that exhibit inherent selectivities and reactivities through host-guest interactions have inspired widesprea
Asymmetric Transfer Hydrogenation of Aryl Heteroaryl Ketones using Noyori-Ikariya Catalysts
Zheng, Ye,Martinez-Acosta, Jaime A.,Khimji, Mohammed,Barbosa, Luiz C. A.,Clarkson, Guy J.,Wills, Martin
, p. 4384 - 4391 (2021/08/23)
A range of ketones flanked by a combination of an aromatic and a heterocyclic ring (furan, thiophene, N-methylimidazole) were reduced under asymmetric transfer hydrogenation (ATH) conditions. Using a range of [(arene)Ru(TsDPEN)Cl] precatalysts, including tethered derivatives, the reduction enantioselectivity was high (up to 99 % ee) in cases where the aromatic ring contained an ortho-substituent. The enantioselectivity is influenced by a combination of steric and electronic factors which for the furan and thiophene series, follow literature precedents. In the case of the N-methylimidazole-containing ketones, an unexpected switch in enantioselectivity took place upon variation of the opposing aromatic group. Pyrrole- containing ketones were resistant to reduction. This study demonstrates the asymmetric transfer hydrogenation (ATH) of a range of hindered heterocyclic ketones, in high conversion and ee, using Noyori-Ikariya catalysts.
Isomerization of Propargyl Ethers of 2-Hydroxyoxiranes to Furan Derivatives on Silver Catalysts
Talybov, G. M.
, p. 1153 - 1156 (2021/08/06)
Abstract: It was shown that propargyl ethers of 2-hydroxyoxiranes in the presence of asilver salt of a molybdenum heteropoly acid as a catalyst leads to the formationof furan derivatives with a yield of up to 62.3% and highregioselectivity. [Figure not available: see fulltext.]
Divergent Synthesis of Dihydropyranone Stereoisomers via N-Heterocyclic Carbene Catalysis
Zhao, Changgui,Wang, Jian
supporting information, p. 1668 - 1672 (2019/02/19)
We recently developed a novel chiral N-heterocyclic carbene (NHC) catalyzed dynamic kinetic enantioselective acylation (DKEA) and dynamic kinetic diastereoselective acylation (DKDA) of Achmatowicz rearrangement products to generate useful intermediates for the further synthesis of carbohydrates. In this update, we describe a divergent NHC catalytic strategy for the stereoselective preparation of all four isomers starting from a common racemic precursor. The present report provides easy access to diverse optically pure dihydropyranones. (Figure presented.).
Development of Chiral C2-Symmetric N-Heterocyclic Carbene Rh(I) Catalysts through Control of Their Steric Properties
Abadie, Marc-Antoine,Macintyre, Kirsty,Boulho, Cédric,Hoggan, Peter,Capet, Frédéric,Agbossou-Niedercorn, Francine,Michon, Christophe
, p. 536 - 543 (2019/01/14)
Chiral square-planar Rh(I) complexes based on new C2-symmetric NHC ligands have been synthesized selectively in a few steps as single diastereoisomers. These chiral precatalysts were applied to the asymmetric transfer hydrogenation of 1-phenylp
Nickel Catalyzed Intermolecular Carbonyl Addition of Aryl Halide
Ishida, Seima,Suzuki, Hiroyuki,Uchida, Seiichiro,Yamaguchi, Eiji,Itoh, Akichika
supporting information, p. 7483 - 7487 (2019/12/11)
In this study, we develop a nickel-catalyzed carbonyl arylation reaction employing aldehydes with aryl and allyl halides. Various aryl, α,β-unsaturated aldehyde and aliphatic aldehydes can be converted into their corresponding secondary alcohols in moderate-to-high yields. In addition, we extended this approach to develop an asymmetric reductive coupling reaction that combines nickel salts with chiral bisoxazoline ligands to give secondary alcohols with moderate enantioselectivity.
Chloroperoxidase-Catalyzed Achmatowicz Rearrangements
Thiel, Daniel,Blume, Fabian,J?ger, Christina,Deska, Jan
, p. 2717 - 2725 (2018/05/14)
Chloroperoxidase from Caldariomyces fumago catalyzes the selective oxidation of furfuryl alcohols in an Achmatowicz-type ring expansion. In combination with glucose oxidase as oxygen-activating biocatalyst, a purely enzymatic, aerobic protocol for the synthesis of 6-hydroxypyranone building blocks is obtained. Thanks to an only modest stereochemical bias of the oxygenating heme protein, optically active alcohols of either configuration are converted without a significant mismatch opening up opportunities for enantioselective multienzymatic cascades. Balancing the oxidase-driven aerobic activation, extended enzyme half-lives and productive conversion of poorly soluble and slowly reacting substrates can be achieved with high yields of the six-membered O-heterocycles.
Scandium as a pre-catalyst for the deoxygenative allylation of benzylic alcohols
?oli?, Ivan,Seankongsuk, Pattarakiat,Loh, Joanna Kejun,Vilaivan, Tirayut,Bates, Roderick W.
supporting information, p. 119 - 123 (2017/12/27)
Scandium triflate is an effective pre-catalyst for the deoxygenative allylation of benzylic alcohols with a narrow substrate window. The reaction is shown to proceed through a "hidden Br?nsted acid" mechanism. The reaction is efficient provided that the aryl group is neither too electron rich nor too electron poor. It is shown that this allows useful selectivity. The reaction also works for benzyhydryl alcohols with broader scope. The reaction may also be catalysed by Nafion.
Visible-light-mediated achmatowicz rearrangement
Plutschack, Matthew B.,Seeberger, Peter H.,Gilmore, Kerry
supporting information, p. 30 - 33 (2017/11/28)
Visible-light-mediated photoredox catalysis is a viable method to access highly reactive intermediates from cheap, readily available, and shelfstable reagents to perform clean chemical transformations. Here, we report the first photoredox-catalyzed Achmatowicz reaction of furfuryl alcohol derivatives to produce functionalized dihydropyranones while only forming easily separable NaHSO4 as a byproduct. The water solubility of the byproduct facilitates direct Boc-protection of the resulting hemiacetal without the need for column purification. The reaction is very robust and permits the use of various aqueous solutions and light sources including sunlight.
The inexpensive additive N-methylmorpholine effectively decreases the equivalents of nucleophiles in the catalytic highly enantioselective arylation of aryl aldehydes
Wang, Pei,Liu, Yue,Zhang, Ya-Lun,Da, Chao-Shan
supporting information, p. 443 - 450 (2017/07/25)
Highly enantioselective arylation of aryl aldehydes catalyzed by (S)-H8-BINOL-Ti(Oi-Pr)2 complex in the presence of N-methylmorpholine (NMM) as an effective and inexpensive additive is described for the first time. We found high enan
