75337-05-2Relevant articles and documents
Tuning of α-Silyl Carbocation Reactivity into Enone Transposition: Application to the Synthesis of Peribysin D, E-Volkendousin, and E-Guggulsterone
Athawale, Paresh R.,Zade, Vishal M.,Rama Krishna, Gamidi,Reddy, D. Srinivasa
, p. 6642 - 6647 (2021/09/02)
A reliable method for enone transposition has been developed with the help of silyl group masking. Enantio-switching, substituent shuffling, and Z-selectivity are the highlights of the method. The developed method was applied for the first total synthesis of peribysin D along with its structural revision. Formal synthesis of E-guggulsterone and E-volkendousin was also claimed using a short sequence.
BENZIMIDAZOLE AND HYDROGENATED CARBAZOLE DERIVATIVES AS GPX4 INHIBITORS
-
, (2021/03/05)
This present disclosure relates to compounds with ferroptosis inducing activity, a method of treating a subject with cancer with the compounds, and combination treatments with a second therapeutic agent.
Bidentate Nitrogen-Ligated I(V) Reagents, Bi(N)-HVIs: Preparation, Stability, Structure, and Reactivity
Xiao, Xiao,Roth, Jessica M.,Greenwood, Nathaniel S.,Velopolcek, Maria K.,Aguirre, Jordan,Jalali, Mona,Ariafard, Alireza,Wengryniuk, Sarah E.
, p. 6566 - 6576 (2021/05/06)
Hypervalent iodine(V) reagents are a powerful class of organic oxidants. While the use of I(V) compounds Dess-Martin periodinane and IBX is widespread, this reagent class has long been plagued by issues of solubility and stability. Extensive effort has been made for derivatizing these scaffolds to modulate reactivity and physical properties but considerable room for innovation still exists. Herein, we describe the preparation, thermal stability, optimized geometries, and synthetic utility of an emerging class of I(V) reagents, Bi(N)-HVIs, possessing datively bound bidentate nitrogen ligands on the iodine center. Bi(N)-HVIs display favorable safety profiles, improved solubility, and comparable to superior oxidative reactivity relative to common I(V) reagents. The highly modular synthesis and in situ generation of Bi(N)-HVIs provides a novel and convenient screening platform for I(V) reagent and reaction development.
CeO2-Supported Pd(II)-on-Au Nanoparticle Catalyst for Aerobic Selective α,β-Desaturation of Carbonyl Compounds Applicable to Cyclohexanones
Jin, Xiongjie,Mizuno, Noritaka,Takei, Daisuke,Yabe, Tomohiro,Yamaguchi, Kazuya,Yatabe, Takafumi
, p. 5057 - 5063 (2020/05/27)
Direct selective desaturation of carbonyl compounds to synthesize α,β-unsaturated carbonyl compounds represents an environmentally benign alternative to classical stepwise procedures. In this study, we designed an ideal CeO2-supported Pd(II)-on-Au nanoparticle catalyst (Pd/Au/CeO2) and successfully achieved heterogeneously catalyzed selective desaturation of cyclohexanones to cyclohexenones using O2 in air as the oxidant. Besides cyclohexenones, various bioactive enones can also be synthesized from the corresponding saturated ketones under open air conditions in the presence of Pd/Au/CeO2. Preliminary mechanistic studies revealed that α-C-H bond cleavage in the substrates is the turnover-limiting step of this desaturation reaction.
Palladium-Mediated Remote Functionalization in γ- And ?-Arylations and Alkenylations of Unblocked Cyclic Enones
Saini, Gaurav,Mondal, Arpan,Kapur, Manmohan
, p. 9071 - 9075 (2019/11/14)
We report herein an extensive investigation of simple and regioselective endo- as well as exo-γ-arylations of silyl-dienol ethers of unblocked cyclic enones with the utilization of palladium-catalyzed, modified Kuwajima-Urabe conditions. We have also successfully explored a new exo-?-arylation of silyl-trienol ethers of π-extended cyclic enones. In addition, we also report, herein, exclusive γ- and ?-alkenylation of silyl-dienol and silyl-trienol ethers of cyclic enones.
Regioselective Iridium-Catalyzed Asymmetric Monohydrogenation of 1,4-Dienes
Liu, Jianguo,Krajangsri, Suppachai,Singh, Thishana,De Seriis, Giulia,Chumnanvej, Napasawan,Wu, Haibo,Andersson, Pher G.
, p. 14470 - 14475 (2017/10/24)
A highly efficient regio- and enantioselective monohydrogenation of 1,4-dienes has been realized using an iridium catalyst with a chiral N,P-ligand under mild conditions. The substrate scope was studied and included both unfunctionalized as well as functionalized substituents on the meta- or para-position. Substrates having substituents with functionalities such as silyl protected alcohols or ketals were monohydrogenated in high regioselectivity and high enantiomeric excess (up to 98% ee).
Au-Pd alloy nanoparticles supported on layered double hydroxide for heterogeneously catalyzed aerobic oxidative dehydrogenation of cyclohexanols and cyclohexanones to phenols
Jin, Xiongjie,Taniguchi, Kento,Yamaguchi, Kazuya,Mizuno, Noritaka
, p. 5371 - 5383 (2016/07/29)
Phenol, an important industrial chemical, is widely produced using the well-developed cumene process. However, demand for the development of a novel alternative method for synthesizing phenol from benzene has been increasing. Herein, we report a novel system for the synthesis of phenols through aerobic oxidative dehydrogenation of cyclohexanols and cyclohexanones, including ketone-alcohol (KA) oil, catalyzed by Mg-Al-layered double hydroxide (LDH)-supported Au-Pd alloy nanoparticles (Au-Pd/LDH). Alloying of Au and Pd and basicity of LDH are key factors in achieving the present transformation. Although monometallic Au/LDH, Pd/LDH, and their physical mixture showed almost no catalytic activity, Au-Pd/LDH exhibited markedly high catalytic activity for the dehydrogenative phenol production. Mechanistic studies showed that β-H elimination from Pd-enolate species is accelerated by Au species, likely via electronic ligand effects. Moreover, the effect of supports was critical; despite the high catalytic performance of Au-Pd/LDH, Au-Pd bimetallic nanoparticles supported on Al2O3, TiO2, MgO, and CeO2 were ineffective. Thus, the basicity of LDH plays a deterministic role in the present dehydrogenation possibly through its assistance in the deprotonation steps. The synthetic scope of the Au-Pd/LDH-catalyzed system was very broad; various substituted cyclohexanols and cyclohexanones were efficiently converted into the corresponding phenols, and N-substituted anilines were synthesized from cyclohexanones and amines. In addition, the observed catalysis was truly heterogeneous, and Au-Pd/LDH could be reused without substantial loss of its high performance. The present transformation is scalable, utilizes O2 in air as the terminal oxidant, and generates water as the only by-product, highlighting the potential practical utility and environmentally benign nature of the present transformation. Dehydrogenative aromatization of cyclohexanols proceeds through (1) oxidation of cyclohexanols to cyclohexanones; (2) dehydrogenation of cyclohexanones to cyclohexenones; and (3) disproportionation of cyclohexenones to afford the desired phenols. In the present Au-Pd/LDH-catalyzed transformation, the oxidation of the Pd-H species is included in the rate-determining step.
Bismuth-substituted "sandwich" type polyoxometalate catalyst for activation of peroxide: Umpolung of the peroxo intermediate and change of chemoselectivity
Amanchi, Srinivasa Rao,Khenkin, Alexander M.,Diskin-Posner, Yael,Neumann, Ronny
, p. 3336 - 3341 (2015/06/16)
The epoxidation of alkenes with peroxides by WVI, MoVI, VV, and TiIV compounds is well established, and it is well accepted that the active intermediate peroxo species are electrophilic toward nucleophilic substrates. Polyoxotungstates, for example, those of the "sandwich" structure, [WZn(TM-L)2(ZnW9O34)2]q- in which TM = transition metal and L = H2O, have in the past been found to be excellent epoxidation catalysts. It has now been found that substituting the Lewis basic BiIII into the terminal position of the "sandwich" polyoxometalate structure to yield [Zn2BiIII2(ZnW9O34)2]14- leads to an apparent umpolung of the peroxo species and formation of a nucleophilic peroxo intermediate. There are two lines of evidence that support the formation of a reactive nucleophilic peroxo intermediate: (1) More electrophilic sulfoxides are more reactive than more nucleophilic sulfides, and (2) nonfunctionalized aliphatic alkenes and dienes showed ene type reactivity rather than epoxidation pointing toward "dark" formation of singlet oxygen from the nucleophilic intermediate peroxo species. Allylic alcohols reacted much faster than alkenes but showed chemoselectivity toward C-H bond activation of the alcohol and formation of aldehydes or ketones rather than epoxidation. This explained via alkoxide formation at the BiIII center followed by oxidative β-elimination.
Broadening the scope of Baeyer-Villiger monooxygenase activities toward α,β-unsaturated ketones: A promising route to chiral enol-lactones and ene-lactones
Reignier,De Berardinis,Petit,Mariage,Hamze,Duquesne,Alphand
supporting information, p. 7793 - 7796 (2014/07/08)
Three regiodivergent Baeyer-Villiger mono-oxygenases (enantioselectively) oxidized a series of cyclic α,β-unsaturated ketones into (chiral) either enol-lactones or ene-lactones. An easy-to-use and efficient biocatalytic process based on a host-microorganism deprived of unwanted activities (knock-out mutant) was developed to enable the exclusive synthesis of unsaturated lactones. This journal is the Partner Organisations 2014.
Aerobic double dehydrogenative cross coupling between cyclic saturated ketones and simple arenes
Gigant, Nicolas,Baeckvall, Jan-E.
supporting information, p. 5890 - 5894 (2014/05/20)
The synthesis of 3-aryl-2-cyclohexenones is a topic of current interest as they are not only privileged structures in bioactive molecules, but they are also relevant feedstocks for the synthesis of substituted phenols or anilines, which are ubiquitous structural elements both in drug design and medicinal chemistry. A simple and sustainable one-pot aerobic double dehydrogenative reaction under mild conditions for the introduction of arenes in the β-position of cyclic ketones has been developed. Starting from the corresponding saturated ketone, this reaction sequence proceeds under relatively low Pd catalyst loading and involves catalytic amounts of electron-transfer mediators (ETMs) under ambient oxygen pressure. A simple and sustainable one-pot aerobic double dehydrogenative reaction under mild conditions for the introduction of arenes in the β-position of cyclic ketones has been developed (see scheme). Starting from the corresponding saturated ketone, this reaction sequence proceeds under relatively low Pd catalyst loading and involves catalytic amounts of electron-transfer mediators (ETMs) under ambient oxygen pressure.
