446-65-1Relevant academic research and scientific papers
Highly enantioselective construction of CF3-bearing all-carbon quaternary stereocenters: Hiral spiro-fused bisoxazoline ligands with 1,1′-binaphthyl sidearm for asymmetric Michael-type Friedel-Crafts reaction
Bao, Robert Li-Yuan,Fu, Kang,Shi, Lei
, (2021/11/27)
A novel class of chiral spiro-fused bisoxazoline ligands possessing a deep chiral pocket was prepared. The developed ligands have been employed in the nickel-catalyzed highly enantioselective Michael-type Friedel-Crafts reaction, affording the products bearing a trifluoromethylated all-carbon quaternary stereocenter with moderate to excellent yields (up to 99%) and good to excellent enantioselectivies (up to > 99.9% ee). Moreover, a proposed model of chiral pocket revealed that the attack of indole from the Re-face of β-CF3-β-disubstituted nitroalkene was favorable.
One-Pot Successive Turbo Grignard Reactions for the Facile Synthesis of α-Aryl-α-Trifluoromethyl Alcohols
Kani, Ryunosuke,Inuzuka, Toshiyasu,Kubota, Yasuhiro,Funabiki, Kazumasa
supporting information, p. 4487 - 4493 (2020/06/01)
A novel straightforward one-pot methodology for two successive turbo Grignard reagent (iPrMgCl·LiCl) reactions, was developed for a facile synthesis of α-aryl-α-trifluoromethyl alcohols, motifs of value in pharmaceutical chemistry. The method displayed broad functional group tolerance, including reducible groups. Dual roles of iPrMgCl·LiCl were exploited in the tandem reaction with commercially available iodoarenes or iodoheteroarenes and 2,2,2-trifluoroethyl trifluoroacetate. The process encompasses three successive reactions in a one-pot process: the iPrMgCl·LiCl-mediated iodine/magnesium-exchange reaction of iodoarenes or iodoheteroarenes; nucleophilic addition of various generated aryl or heteroarylmagnesium reagents to 2,2,2-trifluoroethyl trifluoroacetate; and the reduction of in-situ generated aryl trifluoromethyl ketones with iPrMgCl·LiCl, to produce the corresponding α-aryl or α-heteroaryl-α-trifluoromethyl alcohols bearing various substituents, including reducible functional groups in good to excellent yields.
Synthesis of Unsymmetric Triarylmethanes Bearing CF 3-Substituted All-Carbon Quaternary Stereocenters: 1,6-Arylation of δ-Trifluo romethyl Substituted para -Quinone Methides
Ma, Yingang,Pang, Jingxiang,Pan, Xiaoguang,Ma, Shutao,Liu, Xigong,Liu, Lei
supporting information, p. 1619 - 1622 (2020/09/15)
Pre-synthesized δ-CF 3-δ-aryl-disubstituted para -quinone methides bearing δ-substituents were identified as isolable and storable substrates for 1,6-arylation reactions. A broad range of electron-rich arenes and heteroarenes participated in the arylation process, furnishing a wide array of unsymmetrical CF 3-substituted triarylmethanes in high efficiency. The mild and expeditious protocol exhibited broad scopes of both arene and para -quinone methide components.
A Hammett Study of Clostridium acetobutylicum Alcohol Dehydrogenase (CaADH): An Enzyme with Remarkable Substrate Promiscuity and Utility for Organic Synthesis
Berkowitz, David B.,Kudalkar, Gaurav P.,Lee, Joshua D.,Tiwari, Virendra K.
, p. 237 - 247 (2020/02/18)
Described is a physical organic study of the reduction of three sets of carbonyl compounds by the NADPH-dependent enzyme Clostridium acetobutylicum alcohol dehydrogenase (CaADH). Previous studies in our group have shown this enzyme to display broad substrate promiscuity, yet remarkable stereochemical fidelity, in the reduction of carbonyl compounds, including α-, β- and γ-keto esters (d -stereochemistry), as well as α,α-difluorinated-β-keto phosphonate esters (l -stereochemistry). To better mechanistically characterize this promising dehydrogenase enzyme, we report here the results of a Hammett linear free-energy relationship (LFER) study across three distinct classes of carbonyl substrates; namely aryl aldehydes, aryl β-keto esters and aryl trifluoromethyl ketones. Rates are measured by monitoring the decrease in NADPH fluorescence at 460 nm with time across a range of substrate concentrations for each member of each carbonyl compound class. The resulting v 0 versus [S] data are subjected to least-squares hyperbolic fitting to the Michaelis-Menton equation. Hammett plots of log(V max) versus σ X yield the following Hammett parameters: (i) for p -substituted aldehydes, ρ = 0.99 ± 0.10, ρ = 0.40 ± 0.09; two domains observed, (ii) for p -substituted β-keto esters ρ = 1.02 ± 0.31, and (iii) for p -substituted aryl trifluoromethyl ketones ρ = -0.97 ± 0.12. The positive sign of ρ indicated for the first two compound classes suggests that the hydride transfer from the nicotinamide cofactor is at least partially rate-limiting, whereas the negative sign of ρ for the aryl trifluoromethyl ketone class suggests that dehydration of the ketone hydrate may be rate-limiting for this compound class. Consistent with this notion, examination of the 13 C NMR spectra for the set of p -substituted aryl trifluo romethyl ketones in 2percent aqueous DMSO reveals significant formation of the hydrate (gem -diol) for this compound family, with compounds bearing the more electron-withdrawing groups showing greater degrees of hydration. This work also presents the first examples of the CaADH-mediated reduction of aryl trifluoromethyl ketones, and chiral HPLC analysis indicates that the parent compound α,α,α-trifluoroacetophenone is enzymatically reduced in 99percent ee and 95percent yield, providing the (S)-stereoisomer, suggesting yet another compound class for which this enzyme displays high enantioselectivity.
Asymmetric Hydrogenation of Aryl Perfluoroalkyl Ketones Catalyzed by Rhodium(III) Monohydride Complexes Bearing Josiphos Ligands
Brüning, Fabian,Nagae, Haruki,K?ch, Daniel,Mashima, Kazushi,Togni, Antonio
supporting information, p. 10818 - 10822 (2019/07/31)
The asymmetric hydrogenation of 2,2,2-trifluoroacetophenones and aryl perfluoroalkyl ketones was developed using a unique, well-defined chloride-bridged dinuclear rhodium(III) complex bearing Josiphos-type diphosphine ligands. These complexes were prepared from [RhCl(cod)]2, Josiphos ligands, and hydrochloric acid. As catalyst precursors, they allow for the efficient and enantioselective synthesis (up to 99 % ee) of chiral secondary alcohols with perfluoroalkyl groups. This system does not require an activating base for the hydrogenation of 2,2,2-trifluoroacetophenones. Additionally, the enantioselective C=O hydrogenations of 2-phenyl-3-(haloacetyl)-indoles, a class of privileged structures in medicinal chemistry, is reported for the first time.
Oxidation of α-trifluoromethyl and non-fluorinated alcohols: Via the merger of oxoammonium cations and photoredox catalysis
Pistritto, Vincent A.,Paolillo, Joshua M.,Bisset, Kathryn A.,Leadbeater, Nicholas E.
, p. 4715 - 4719 (2018/07/06)
We present an alcohol oxidation strategy to access α-trifluoromethyl ketones (TFMKs) merging catalytic oxoammonium cation oxidation with visible-light photoredox catalysis. This work uses 4-acetamido-(2,2,6,6-tetramethyl-piperidin-1-yl)oxyl as an organic oxidant capable of generating TFMKs in good yields. The methodology serves as an improvement over previous reports of an analogous oxidation strategy requiring superstoichiometric quantities of oxidant. Both primary and secondary non-fluorinated alcohols can also be oxidised in good yields.
Visible light-promoted umpolung coupling of aryl tri-/difluoroethanones with 2-alkenylpyridines
Xu, Xiao,Min, Qing-Qiang,Li, Na,Liu, Feng
supporting information, p. 11017 - 11020 (2018/10/08)
Tertiary alcohols bearing a trifluoromethyl group are of considerable medicinal interest. Using an umpolung strategy, we herein report the first intermolecular reductive cross-coupling of aryl tri-/difluoroethanones with 2-alkenylpyridines with the aid of a Br?nsted acid catalyst upon visible-light irradiation. This metal-free reaction is operationally simple and performed at ambient temperature, allowing access to desired tertiary alcohols with tri-/difluoromethyl groups in moderate to excellent yields. The commercially available and easily handled Hantzsch ester effectively serves as an electron donor, as well as a hydrogen atom source.
HORMONE RECEPTOR MODULATORS FOR TREATING METABOLIC CONDITIONS AND DISORDERS
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Page/Page column 288, (2018/03/25)
The invention relates to activators of FXR useful in the treatment of autoimmune disorders, liver disease, intestinal disease, kidney disease, cancer, and other diseases in which FXR plays a role, having the Formula (I): (I), wherein L1, A, X1, X2, R1, R2, and R3 are described herein.
Is Magnetic Bistability of Carbenes a General Phenomenon? Isolation of Simple Aryl(trifluoromethyl)carbenes in Both Their Singlet and Triplet States
Tsegaw, Yetsedaw A.,Kadam, Pritam E.,T?tsch, Niklas,Sanchez-Garcia, Elsa,Sander, Wolfram
, p. 12310 - 12316 (2017/09/12)
p-Tolyl(trifluoromethyl)carbene and the related fluorenyl(trifluoromethyl)carbene were synthesized in solid argon and characterized by IR, UV-vis, and electron paramagnetic resonance spectroscopy as well as by quantum mechanical calculations. The carbenes
FLUOROALKYLATING AGENT
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Paragraph 1333-1334, (2018/01/11)
Problem to be Solved It is intended to provide an industrially preferable fluoroalkylating agent and use thereof. Solution The present invention provides a fluoroalkylating agent represented by the general formula (1) wherein R1 is a C1 to C8 fluoroalkyl group; R2 and R3 are each independently a C1 to C12 alkyl group or the like; Y1 to Y4 are each independently a hydrogen atom, a halogen atom, or the like; and X? is a monovalent anion. A compound of the general formula (3): R4—S—R1 having an introduced C1 to C8 fluoroalkyl group is easily obtained by reacting a compound of the general formula (2): R4—S—Z wherein R4 is a hydrocarbon group or the like; and Z is a leaving group, with the compound of the general formula (1).
