- Aldehyde-catalyzed epoxidation of unactivated alkenes with aqueous hydrogen peroxide
-
The organocatalytic epoxidation of unactivated alkenes using aqueous hydrogen peroxide provides various indispensable products and intermediates in a sustainable manner. While formyl functionalities typically undergo irreversible oxidations when activating an oxidant, an atropisomeric two-axis aldehyde capable of catalytic turnover was identified for high-yielding epoxidations of cyclic and acyclic alkenes. The relative configuration of the stereogenic axes of the catalyst and the resulting proximity of the aldehyde and backbone residues resulted in high catalytic efficiencies. Mechanistic studies support a non-radical alkene oxidation by an aldehyde-derived dioxirane intermediate generated from hydrogen peroxide through the Payne and Criegee intermediates.
- Kokotos, Christoforos G.,Kokotou, Maroula G.,Lotter, Dominik,Sparr, Christof,Triandafillidi, Ierasia
-
p. 10191 - 10196
(2021/08/12)
-
- Mechanochemical Synthesis of 1,2-Diketoindolizine Derivatives from Indolizines and Epoxides Using Piezoelectric Materials
-
A simple and efficient mechanochemical-induced approach for the synthesis of 1,2-diketoindolizine derivatives has been developed. BaTiO3 was used as the piezoelectric material in this transformation. This method features no usage of solvent, simple experimental operation, scalable potential, and high conversion efficiency, which make it attractive and practical.
- Wang, Yumei,Zhang, Ziwu,Deng, Lichan,Lao, Tianfeng,Su, Zhengquan,Yu, Yue,Cao, Hua
-
p. 7171 - 7176
(2021/09/14)
-
- Catalyst-Free Electrophilic Ring Expansion of N-Unprotected Aziridines with α-Oxoketenes to Efficient Access 2-Alkylidene-1,3-Oxazolidines
-
2-(2-Oxoalkylidene)-1,3-oxazolidine derivatives were synthesized in good to excellent yields regiospecifically through the catalyst-free electrophilic ring expansion of N-unprotected aziridines and the ketene C=O double bond of α-oxoketenes, in situ generated from the microwave-assisted Wolff rearrangement of 2-diazo-1,3-diketones. The ring expansion predominantly underwent an SN1 process and the hydrogen bond decides the (E)-configuration of products. (Figure presented.).
- Chen, Xingpeng,Huang, Zhengshuo,Xu, Jiaxi
-
supporting information
p. 3098 - 3108
(2021/05/10)
-
- TAU-PROTEIN TARGETING COMPOUNDS AND ASSOCIATED METHODS OF USE
-
The present disclosure relates to bifunctional compounds, which find utility as modulators of tan protein. In particular, the present disclosure is directed to bifunctional compounds, which contain on one end a VHL or cereblon ligand which binds to the E3 ubiquitin ligase and on the other end a moiety which binds tan protein, such that tan protein is placed in proximity to the ubiquitin ligase to effect degradation (and inhibition) of tan. The present disclosure exhibits a broad range of pharmacological activities associated with degradation/inhibition of tan protein. Diseases or disorders that result from aggregation or accumulation of tan protein are treated or prevented with compounds and compositions of the present disclosure.
- -
-
Paragraph 0350
(2021/02/12)
-
- Kinetic resolution ofN-aryl β-amino alcoholsviaasymmetric aminations of anilines
-
An efficient kinetic resolution ofN-aryl β-amino alcohols has been developedviaasymmetricpara-aminations of anilines with azodicarboxylates enabled by chiral phosphoric acid catalysis. Broad substrate scope and high kinetic resolution performances were afforded with this method. Control experiments supported the critical roles of the NH and OH group in these reactions.
- Guo, Zheng,Xie, Jinglei,Hu, Tao,Chen, Yunrong,Tao, Houchao,Yang, Xiaoyu
-
supporting information
p. 9394 - 9397
(2021/09/22)
-
- MeOTf/KI-catalyzed efficient synthesis of 2-arylnaphthalenesviacyclodimerization of styrene oxides
-
The MeOTf/KI-catalyzed synthesis of 2-arylnaphthalene derivatives from aryl ethylene oxides in alcohol under ambient conditions is described. The present protocol has a higher atom efficiency and wider substrate applicability with excellent yields. The reaction proceeded using the aryl ethylene oxides to give 2-arylnaphthalenes either in homo-coupling or in cross-coupling. The reaction could also be carried out at the gram scale in minutes.
- Chen, Chao,Xi, Chanjuan,Zhang, Zeyu,Zou, Song
-
supporting information
p. 8559 - 8565
(2021/10/20)
-
- MeOTf-catalyzed formal [4?+?2] annulations of styrene oxides with alkynes leading to polysubstituted naphthalenes through sequential electrophilic cyclization/ring expansion
-
MeOTf-catalyzed formal [4 + 2] annulation of styrene oxides with alkynes to afford polysubstituted naphthalenes has been realized, which undergoes sequential electrophilic cyclization/ring expansion. A range of substrates were tolerated in the formation of naphthalene derivatives with high regioselectivity in satisfactory yields. The reaction could also be carried out on gram scale.
- Chen, Chao,Xi, Chanjuan,Zhang, Zeyu,Zou, Song
-
supporting information
(2021/12/30)
-
- Aerobic epoxidation of styrene over Zr-based metal-organic framework encapsulated transition metal substituted phosphomolybdic acid
-
Catalytic epoxidation of styrene with molecular oxygen is regarded as an eco-friendly alternative to producing industrially important chemical of styrene oxide (STO). Recent efforts have been focused on developing highly active and stable heterogeneous catalysts with high STO selectivity for the aerobic epoxidation of styrene. Herein, a series of transition metal monosubstituted heteropolyacid compounds (TM-HPAs), such as Fe, Co, Ni or Cu-monosubstituted HPA, were encapsulated in UiO-66 frameworks (denoted as TM-HPA@UiO-66) by direct solvothermal method, and their catalytic properties were investigated for the aerobic epoxidation of styrene with aldehydes as co-reductants. Among them, Co-HPA@UiO-66 showed relatively high catalytic activity, stability and epoxidation selectivity at very mild conditions (313 K, ambient pressure), that can achieve 82 % selectivity to STO under a styrene conversion of 96 % with air as oxidant and pivalaldehyde (PIA) as co-reductant. In addition, the hybrid composite catalyst can also efficiently catalyze the aerobic epoxidation of a variety of styrene derivatives. The monosubstituted Co atoms in Co-HPA@UiO-66 are the main active sites for the aerobic epoxidation of styrene with O2/PIA, which can efficiently converting styrene to the corresponding epoxide through the activation of the in-situ generated acylperoxy radical intermediate.
- Hu, Dianwen,Song, Xiaojing,Zhang, Hao,Chang, Xinyu,Zhao, Chen,Jia, Mingjun
-
-
- Iodobenzene-catalyzed oxidative cleavage of olefins to carbonyl compounds
-
A metal-free approach for the oxidative cleavage of carbon–carbon double bonds of olefins to carbonyl compounds was established by using oxidant m-CPBA and non-metallic organocatalyst PhI in toluene/H2O. A broad scope of aromatic olefins was used. All the reactions proceeded smoothly at 35 °C in short reaction time to furnish the respective mono- and double carbonyl compounds selectively in moderate to good yields.
- Du, Lele,Wang, Zechao,Wu, Junliang
-
supporting information
(2020/07/20)
-
- Highly selective and efficient olefin epoxidation with pure inorganic-ligand supported iron catalysts
-
Over the past two decades, there have been major developments in the transition iron-catalyzed selective oxidation of alkenes to epoxides; a common structure found in drug, isolated natural products, and fine chemicals. Many of these approaches have enabled highly efficient and selective epoxidation of alkenes via the design of specialized ligands, which facilitates to control the activity and selectivity of the reactions catalyzed by iron atom. Herein, we report the development of the olefin epoxidation with inorganic-ligand supported iron-catalysts using 30% H2O2 as an oxidant, and the mechanism is similar to iron-porphyrin type. With the catalyst 1, (NH4)3[FeMo6O18(OH)6], various aromatic and aliphatic alkenes were successfully transformed into the corresponding epoxides with excellent yields as well as chemo- and stereo-selectivity. This catalytic system possesses the advantages of being able to avoid the use of expensive, toxic, air/moisture sensitive and commercially unavailable organic ligands. The generality of this methodology is simple to operate and exhibits high catalytic activity as well as excellent stability, which gives it the potential to be used on an industrial scale, and maybe opens a way for the catalytic oxidation reaction via inorganic-ligand coordinated iron catalysis.
- Zhou, Zhuohong,Dai, Guoyong,Ru, Shi,Yu, Han,Wei, Yongge
-
supporting information
p. 14201 - 14205
(2019/10/02)
-
- SO2F2-Mediated Epoxidation of Olefins with Hydrogen Peroxide
-
An inexpensive, mild, and highly efficient epoxidation protocol has been developed involving bubbling SO2F2 gas into a solution of olefin, 30% aqueous hydrogen peroxide, and 4 N aqueous potassium carbonate in 1,4-dioxane at room temperature for 1 h with the formation of the corresponding epoxides in good to excellent yields. The novel SO2F2/H2O2/K2CO3 epoxidizing system is suitable to a variety of olefinic substrates including electron-rich and electron-deficient ones.
- Ai, Chengmei,Zhu, Fuyuan,Wang, Yanmei,Yan, Zhaohua,Lin, Sen
-
p. 11928 - 11934
(2019/10/02)
-
- Kinetics of epoxidation by a Musa paradisiaca chloroperoxidase
-
Epoxidations of indene, styrene, 2-chlorostyrene, 3-chlorostyrene, 4-chlorostyrene, 4-bromostyrene, and naphthalene using Musa paradisiaca plant juice chloroperoxidase in the presence of H2O2 and t-butyl peroxide as oxidants have bee
- Yadav, Pratibha,Khare, Sunil K.,Sharma, Satyawati
-
p. 602 - 609
(2019/05/16)
-
- Synthesis, Crystal Structures, and Catalytic Oxidation of Olefins of Novel Oxomolybdenum(VI) Clusters
-
Abstract: Two Mo(VI) clusters, (H2L)3[Mo7O12(μ2-O)8(μ3-O)4] · 3H2O (I) and (H2L)2[Mo8O14(μ2-O)6
- Peng
-
p. 457 - 466
(2019/07/02)
-
- Controlling Selectivity in Alkene Oxidation: Anion Driven Epoxidation or Dihydroxylation Catalysed by [Iron(III)(Pyridine-Containing Ligand)] Complexes
-
A highly reactive and selective catalytic system comprising Fe(III) and macrocyclic pyridine-containing ligands (Pc-L) for alkene oxidation by using hydrogen peroxide is reported herein. Four new stable iron(III) complexes have been isolated and characterized. Importantly, depending on the anion of the iron(III) metal complex employed as catalyst, a completely reversed selectivity was observed. When X=OTf, a selective dihydroxylation reaction took place. On the other hand, employing X=Cl resulted in the epoxide as the major product. The reaction proved to be quite general, tolerating aromatic and aliphatic alkenes as well as internal or terminal double bonds and both epoxides and diol products were obtained in good yields with good to excellent selectivities (up to 93 % isolated yield and d.r.=99 : 1). The catalytic system proved its robustness by performing several catalytic cycles, without observing catalyst deactivation. The use of acetone as a solvent and hydrogen peroxide as terminal oxidant renders this catalytic system appealing.
- Tseberlidis, Giorgio,Demonti, Luca,Pirovano, Valentina,Scavini, Marco,Cappelli, Serena,Rizzato, Silvia,Vicente, Rubén,Caselli, Alessandro
-
p. 4907 - 4915
(2019/08/30)
-
- Tandem transfer hydrogenation-epoxidation of ketone substrates catalysed by alkene-tethered Ru(ii)-NHC complexes
-
A series of nine cyclopentadienyl Ru(ii)-NHC complexes (1-9) have been synthesised by systematically varying the ligand and/or ligand substituents: η5-C5H4R′ (R′ = H, Me), EPh3 (E = P, As), NHC (Im, BIm), where NHC = Im(R)(R′) (R, R′ = Me, Bn, 4-NO2Bn, C2H4Ph, C4H7). Each of the Ru(ii)-NHC complexes features an N-alkenyl tether to attain bidentate NHC ligands. All complexes found application as catalysts in the tandem transfer hydrogenation and epoxidation reactions of carbonyl substrates. The catalytic activity of the complexes was shown to be similar, with efficiencies of up to 69% conversion after 18 hours and varying alcohol:epoxide selectivity for a variety of electronically diverse carbonyl substrates. Complex 3, with a nitro-containing substituent on the NHC ligand, was the only complex that showed preference for the alcohol product over the epoxide after 18 hours of reaction time.
- Malan, Frederick P.,Singleton, Eric,Van Rooyen, Petrus H.,Landman, Marilé
-
supporting information
p. 8472 - 8481
(2019/06/14)
-
- Nucleophilic Organic Base DABCO-Mediated Chemospecific Meinwald Rearrangement of Terminal Epoxides into Methyl Ketones
-
Nucleophilic organic base DABCO (1,4-diazabicyclo[2.2.2]octane)-mediated Meinwald rearrangement of various epoxides was investigated. 2-Aryl-, alkenyl-, and alkynylepoxides generate the corresponding methyl ketones chemospecifically in good to excellent yields. The current DABCO-mediated Meinwald rearrangement of epoxides features readily accessible starting materials, a wide substrate scope, a transition-metal- and acid-free environment, and chemospecificity in the isomerization of epoxides.
- Li, Siqi,Shi, Yi,Li, Pingfan,Xu, Jiaxi
-
p. 4443 - 4450
(2019/04/30)
-
- Remarkable increase in the rate of the catalytic epoxidation of electron deficient styrenes through the addition of Sc(OTf)3 to the MnTMTACN catalyst
-
The effect of Lewis acids on the catalytic activity of [Mn2(μ-O)3(TMTACN)2](PF6)2 in the epoxidation of styrenes using hydrogen peroxide as the oxidant has shown that the addition of Sc(OTf)3 at low catalytic loading results in a very significant increase in the efficiency of the catalyst and a reduction of the reaction time to only 3 minutes in most cases.
- Nodzewska, Aneta,Watkinson, Michael
-
supporting information
p. 1461 - 1464
(2018/02/19)
-
- Efficient epoxidation reaction of terminal olefins with hydrogen peroxide catalyzed by an iron (II) complex
-
A highly active iron (II) complex that catalyzed epoxidation of terminal olefins with hydrogen peroxide was described. The catalytic system displayed excellent catalytic ability for the selective oxidation of terminal olefins to epoxides with high selecti
- Li, Lu,Song, Hong-Jin,Meng, Xiang-Guang,Yang, Ren-Qiang,Zhang, Ni
-
supporting information
p. 2436 - 2439
(2018/05/24)
-
- Dearomative [2,3] sigmatropic rearrangement of ammonium ylides followed by 1,4-elimination to form α-(ortho-vinylphenyl)amino acid esters
-
A base-induced dearomative [2,3] sigmatropic rearrangement of amino acid ester-derived ammonium salts followed by 1,4-elimination produced α-(ortho-vinylphenyl)amino acid esters. The reaction of azetidine-2-carboxylic acid-derived ammonium salt, (1S,2S,1′R)-3b, proceeded with a perfect N-to-C chirality transfer to afford α-(ortho-vinylphenyl)azetidine-2-carboxylic acid ester, (R)-5 (99% ee). On the other hand, the reaction of glycine-derived ammonium salt (R)-6a, which involves an efficient chirality transfer from a chiral benzylic carbon to an α-carbon of an ester carbonyl giving the optically active α-(ortho-vinylphenyl)glycine ester, (R)-8a (85% ee), was demonstrated. Although this dearomative [2,3] rearrangement followed by 1,4-elimination has limitations with regard to the structures of the substrates, our method provides unique access to substituted α-arylamino acid derivatives.
- Tayama, Eiji,Sotome, Sho
-
supporting information
p. 4833 - 4839
(2018/07/15)
-
- Regio- and chemoselective rearrangement of terminal epoxides into methyl alkyl and aryl ketones
-
The development of the highly active pincer-type rhodium catalyst 2 for the nucleophilic Meinwald rearrangement of functionalised terminal epoxides into methyl ketones under mild conditions is presented. An excellent regio- and chemoselectivity is obtained for the first time for aryl oxiranes.
- Tian, Yingying,Jürgens, Eva,Kunz, Doris
-
supporting information
p. 11340 - 11343
(2018/10/31)
-
- Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds
-
Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular SN2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.
- Li, Siqi,Chen, Xingpeng,Xu, Jiaxi
-
supporting information
p. 1613 - 1620
(2018/03/07)
-
- TAU-PROTEIN TARGETING PROTACS AND ASSOCIATED METHODS OF USE
-
The present disclosure relates to bifunctional compounds, which find utility as modulators of tau protein. In particular, the present disclosure is directed to bifunctional compounds, which contain on one end a VHL or cereblon ligand which binds to the E3 ubiquitin ligase and on the other end a moiety which binds tau protein, such that tau protein is placed in proximity to the ubiquitin ligase to effect degradation (and inhibition) of tau. The present disclosure exhibits a broad range of pharmacological activities associated with degradation/inhibition of tau protein. Diseases or disorders that result from aggregation or accumulation of tau protein are treated or prevented with compounds and compositions of the present disclosure.
- -
-
Paragraph 0644-0646
(2018/05/24)
-
- Synthesis, crystal structures, and catalytic oxidation of olefins of dioxomolybdenum(VI) complexes with aroylhydrazone ligands
-
Two Mo(VI) aroylhydrazone complexes, cis-[MoO2(L1)(CH3OH)] (I) and cis-[MoO2(L2)(CH3OH)] (II), derived from 2-bromo-N'-(3,5-dibromo-2-hydroxybenzylidene)benzohydrazide (H2L1
- Peng
-
p. 189 - 195
(2017/03/30)
-
- Potassium phosphate-catalyzed one-pot synthesis of 3-aryl-2-oxazolidinones from epoxides, amines, and atmospheric carbon dioxide
-
Potassium phosphate was found to be a highly active catalyst in the three-component cycloaddition of amines, epoxides, and carbon dioxide in DMF at ambient temperature to form 3-aryl-2-oxazolidinones. Atmospheric CO2 and a broad range of amines were employed in this transformation. Aryl isocyanate and 1,2-aminoalcohol were generated in situ as key intermediates. This one-pot reaction is applicable to a variety of terminal epoxides and amines. The key advantages are high yields, simple work-up, inexpensive catalysts, and a practical ten gram-scale synthesis.
- Seo, Ue Ryung,Chung, Young Keun
-
supporting information
p. 803 - 808
(2017/08/15)
-
- Synthesis, characterization, and crystal structures of dioxomolybdenum(VI) complexes with O,N,N type tridentate hydrazone ligands as catalyst for oxidation of olefins
-
The preparation of Mo(VI) hydrazone complexes, cis-[MoO2L1(CH3OH)] (I) and cis-[MoO2L2(CH3OH)] (II), derived from N'-(3-bromo-2-hydroxybenzylidene)-2-chlorobenzohydrazide (H2Lsu
- Zhang,Liang
-
p. 411 - 419
(2017/06/19)
-
- COMPOUNDS AND METHODS FOR THE TARGETED DEGRADATION OF BROMODOMAIN-CONTAINING PROTEINS
-
The present invention relates to bifunctional compounds, which find utility as modulators of targeted ubiquitination, especially inhibitors of a variety of polypeptides and other proteins which are degraded and/or otherwise inhibited by bifunctional compounds according to the present invention. In particular, the present invention is directed to compounds, which contain on one end a VHL ligand which binds to the ubiquitin ligase and on the other end a moiety which binds a target protein such that the target protein is placed in proximity to the ubiquitin ligase to effect degradation (and inhibition) of that protein. The present invention exhibits a broad range of pharmacological activities associated with compounds according to the present invention, consistent with the degradation/inhibition of targeted polypeptides.
- -
-
Paragraph 00216
(2017/03/21)
-
- Regioselective hydrosilylation of epoxides catalysed by nickel(II) hydrido complexes
-
Bench-stable nickel fluoride complexes bearing NNN pincer ligands have been employed as precursors for the regioselective hydrosilylation of epoxides at room temperature. A nickel hydride assisted epoxide opening is followed by the cleavage of the newly formed nickel oxygen bond by σ-bond metathesis with a silane.
- Wenz, Jan,Wadepohl, Hubert,Gade, Lutz H.
-
supporting information
p. 4308 - 4311
(2017/04/21)
-
- Two dioxomolybdenum(VI) complexes with hydrazone ligands: synthesis, characterization, crystal structures and catalytic properties
-
A pair of Mo(VI) complexes, [MoO2L1(MeOH)] (1) and [MoO2L2(MeOH)] (2), where L1 and L2 are the dianions of 2-amino-N’-(3-bromo-5-chloro-2-hydroxybenzylidene)benzohydrazide (H2Ls
- Peng, Dong-Lai
-
p. 843 - 848
(2016/10/25)
-
- Gold-catalyzed [4+3] and [4+4]-annulation reactions of: T -butyl propiolate derivatives with epoxides and oxetanes for the construction of 1,4-dioxepane and 1,5-dioxocane cores
-
Gold-catalyzed [4+n]-annulations (n = 3, 4) of tert-butyl propiolate derivatives with epoxides or oxetanes proceed smoothly to yield seven- or eight-membered oxacyclic products efficiently. In the context of the [4+3]-annulations, product analysis reveals a retention of stereochemistry upon the intramolecular SN2 attack of an epoxide. We also report the [4+5]-annulation between one tert-butyl propiolate and γ-lactol, to manifest the utility toward medium-sized rings.
- Sahani, Rajkumar Lalji,Liu, Rai-Shung
-
supporting information
p. 7482 - 7485
(2016/06/14)
-
- Azidolysis of epoxides catalysed by the halohydrin dehalogenase from Arthrobacter sp. AD2 and a mutant with enhanced enantioselectivity: an (S)-selective HHDH
-
Halohydrin dehalogenase from Arthrobacter sp. AD2 catalysed azidolysis of epoxides with high regioselectivity and low to moderate (S)-enantioselectivity (E?=?1–16). Mutation of the asparagine 178 to alanine (N178A) showed increased enantioselectivity towards styrene oxide derivatives and glycidyl ethers. Conversion of aromatic epoxides was catalysed by HheA-N178A with complete enantioselectivity, however the regioselectivity was reduced. As a result of the enzyme-catalysed reaction, enantiomerically pure (S)-β-azido alcohols and (R)-α-azido alcohols (ee???99%) were obtained.
- Mikleu?evi?, Ana,Primo?i?, Ines,Hrenar, Tomica,Salopek-Sondi, Branka,Tang, Lixia,Elenkov, Maja Majeri?
-
p. 930 - 935
(2016/09/13)
-
- Chiral electron deficient ruthenium helical coordination polymer as a catalyst for the epoxidation of substituted styrenes
-
An air and moisture stable ruthenium(III) formate complex [Ru(HCO2)Cl2]n has been synthesized and examined in the epoxidation of substituted styrenes. X-ray crystallographic data of this complex were determined and showed that the formate ligand coordinates to the ruthenium centers in a μ2-η2 fashion (syn, syn). Its asymmetric unit contains one Ru(III) ion together with the half of a formate ligand and one chloride anion, which are bridged between the metal centers, forming a 1-D chain coordination polymer. This electron deficient helical coordination polymer was employed in the epoxidation of para-fluorostyrene, affording the epoxide product in 92% yield. Natural chirality of this coordination polymer is applicable in asymmetric epoxidation reactions.
- Jahromi, Bahareh Tamaddoni,Kharat, Ali Nemati,Zamanian, Sara
-
p. 137 - 140
(2015/01/30)
-
- Continuous and convergent access to vicinyl amino alcohols
-
Five active pharmaceutical ingredients (APIs) containing the vicinyl amino alcohol moiety were synthesized using a convergent chemical assembly system. The continuous system is composed of four flow reaction modules: biphasic oxidation, Corey-Chaykovsky epoxidation, phenol alkylation, and epoxide aminolysis. Judicious choice of reagents and module order allowed for two classes of β-amino alcohols, aryl and aryloxy, to be synthesized in good (27-69%) overall yields.
- Nobuta, Tomoya,Xiao, Guozhi,Ghislieri, Diego,Gilmore, Kerry,Seeberger, Peter H.
-
supporting information
p. 15133 - 15136
(2015/10/12)
-
- Practical iron-catalyzed hydrogen peroxide epoxidation of aromatic olefins using a combination of two kinds of simple picolinate ligands under halide-free reaction conditions
-
High-yield syntheses of epoxides using an iron complex having two types of picolinates in the presence of hydrogen peroxide under halide-free reaction conditions were achieved. The reaction is very simple. The complex, prepared with iron(II) acetate, 2-pi
- Chishiro, Takefumi,Kon, Yoshihiro,Nakashima, Takuya,Goto, Midori,Sato, Kazuhiko
-
supporting information
p. 623 - 627
(2014/05/20)
-
- Catalytic and mechanistic studies into the epoxidation of styrenes using manganese complexes of structurally similar polyamine ligands
-
Two structurally similar polyamine ligands (7 and 8) have been prepared, which differ only by the presence of either a secondary or tertiary nitrogen donor within their N5 donor set. The ligands, in combination with iron and manganese salts, have been screened for their efficacy as catalysts for the epoxidation of styrene, using both hydrogen peroxide and peracetic acid as oxidants. Clear differences in activity between the two systems were observed, with 7 proving most effective in the presence of MnSO4 with H 2O2, whereas ligand 8 proved to be effective with Mn(OTf)2, MnCl2 and Mn(ClO4)2 using peracetic acid as the oxidant. A Hammett analysis of the initial rate kinetics of the optimal systems, combined with analysis by UV-vis spectroscopy, indicates that the small structural differences in the ligands elicit profound changes in the nature of the active species formed. The Royal Society of Chemistry.
- Ilyashenko, Gennadiy,De Faveri, Giorgio,Follier, Thomas,Al-Safadi, Rawan,Motevalli, Majid,Watkinson, Michael
-
p. 1124 - 1134
(2014/02/14)
-
- Chemoenzymatic epoxidation of alkenes based on peracid formation by a Rhizomucor miehei lipase-catalyzed perhydrolysis reaction
-
A chemoenzymatic and selective method for the epoxidation of a series of cyclic and linear alkenes is described. Epoxides have been obtained in moderate to excellent conversions under mild reaction conditions through a two-step sequence, carried out in one-pot. This chemoenzymatic approach is based on a Rhizomucor miehei lipase-catalyzed perhydrolysis reaction to form the corresponding peracid, and subsequent epoxidation of the corresponding alkenes. Reaction parameters with influence in the biotransformation have been optimized specially focusing in the efficient enzymatic peracid formation by means of the correct choice of solvent, oxidant, and peracid precursor. This chemoenzymatic approach has been efficiently applied for the first time, in the regioselective chemical oxidation of (S)-carvone and limonene, both showing an opposite behavior for the oxidation of the internal and external C-C double bond, respectively.
- Méndez-Sánchez, Daniel,Ríos-Lombardía, Nicolás,Gotor, Vicente,Gotor-Fernández, Vicente
-
p. 1144 - 1148
(2014/02/14)
-
- Synthesis of 3-arylcoumarins through N-heterocyclic carbene catalyzed condensation and annulation of 2-chloro-2-arylacetaldehydes with salicylaldehydes
-
The condensation reaction of 2-chloro-2-arylacetaldehyde with salicylaldehyde catalyzed by N-heterocyclic carbene (NHC) leading to 3-arylcoumarin was studied. A number of 3-arylcoumarin derivatives were obtained in good to excellent yields via this umpolung reaction. This reaction is facile and experimentally simple and mild.
- Jiang, Yuansong,Chen, Wanzhi,Lu, Weimin
-
p. 3669 - 3676
(2013/05/08)
-
- METHOD FOR MANUFACTURING AN EPOXY COMPOUND AND METHOD FOR EPOXIDIZING A CARBON-CARBON DOUBLE BOND
-
The present invention provides a method for producing an epoxy compound, comprising oxidizing a carbon-carbon double bond of an organic compound by hydrogen peroxide in the presence of a neutral inorganic salt and a mixed catalyst of a tungsten compound (a), at least one phosphorus compound selected from the group consisting of phosphoric acids, phosphonic acids, and salts thereof (b) and a surfactant (c), and an epoxidizing method comprising oxidizing a carbon-carbon double bond by hydrogen peroxide in the presence of the catalyst and the neutral inorganic salt.
- -
-
Page/Page column 14
(2012/05/07)
-
- Unique salt effect on highly selective synthesis of acid-labile terpene and styrene oxides with a tungsten/Hcatalytic system under acidic aqueous conditions
-
Acid-labile epoxides such as terpene and styrene oxides are effectively synthesized in high yields with good selectivities using tungsten-catalyzed hydrogen peroxide epoxidation in the presence of NaO The salt effect is thought to originate with the addition of a saturated amount of NaOto aqueous H this addition strongly inhibited the undesired hydrolysis of the acid-labile epoxy products, despite the biphasic conditions of substrate as oil phase and Has acidic aqueous phase.
- Hachiya, Houjin,Kon, Yoshihiro,Ono, Yutaka,Takumi, Kiyoshi,Sasagawa, Naoki,Ezaki, Yoichiro,Sato, Kazuhiko
-
experimental part
p. 1672 - 1678
(2012/07/16)
-
- Catalytic epoxidations with pyridinebis(oxazoline)-methyltrioxorhenium complexes and nitrogen-containing catalyst systems
-
The epoxidation of olefins with methyltrioxorhenium (MTO) in the presence of various chiral oxazolines and pyridinebis(oxazoline) ligands as well as achiral N-ligands has been investigated. By applying 1-octene as a model system, reaction conditions were optimized, and high yields and good chemoselectivity (>90 %) were achieved. By applying other aromatic and aliphatic olefins, similar chemoselectivities and up to 19 % enantioselectivity were obtained. The epoxidation of 1-octene using methyltrioxorhenium (MTO) in the presence of pyridinebis(oxazoline) and related ligands is reported. Although excellent chemoselectivity (>90 %) and good yields were obtained, low enantioselectivity was observed. Copyright
- Kiersch, Konstanze,Li, Yuehui,Junge, Kathrin,Szesni, Normen,Fischer, Richard,Kuehn, Fritz E.,Beller, Matthias
-
p. 5972 - 5978
(2013/02/25)
-
- An effective synthesis of acid-sensitive epoxides via oxidation of terpenes and styrenes using hydrogen peroxide under organic solvent-free conditions
-
An efficient epoxidation process for various terpenes and styrenes using a hydrogen peroxide-tungsten catalytic system with organic solvent-and halide-free conditions was developed. In the presence of the catalytic system, Na 2WO4, PhP(O)(OH)2, and [Me(n-C 8H17)3N]HSO4, and under weak acidic conditions, hydrogen peroxide successfully epoxidized -pinene to -pinene oxide in 95% selectivity at 91% conversion, while the previously published conditions utilizing NH2CH2P(O)(OH)2 as a promoter provided no epoxide. Georg Thieme Verlag Stuttgart.
- Kon, Yoshihiro,Hachiya, Houjin,Ono, Yutaka,Matsumoto, Tomohiro,Sato, Kazuhiko
-
experimental part
p. 1092 - 1098
(2011/05/14)
-
- Metallo-macrocycles with labile coordination sites through self assembly: Binuclear phenyl bridged bisbipyridine manganese complexes
-
Self assembly of phenyl bridged bisbipyridines with manganese perchlorate gave structurally different metallo-macrocycles having cis-labile coordination sites which can catalyse olefin epoxidation with peracetic acid in good yield.
- Sham, Kiu-Chor,Zheng, Guoli,Li, Yinyan,Yiu, Shek-Man,Kwong, Hoi-Lun
-
supporting information; experimental part
p. 12060 - 12062
(2012/01/14)
-
- Iron-catalyzed epoxidation of olefins using hydrogen peroxide
-
A practical method of olefin epoxidation was developed by combining FeCl3·6H2O and 1-methylimidazole in acetone using H2O2 as the terminal oxidant. This system showed very good reactivity toward epoxidation of both terminal and substituted alkenes. The use of tridentate and tetradentate amine-bis(phenolate) ligands as additives was also examined. Modest improvement in selectivity was achieved if a bulky tridentate ligand was used. Generally, however, the simple catalyst system involving ferric chloride, 1-methylimidazole and dilute H2O 2 in acetone proved most successful in achieving good to excellent yields of epoxide products for a number of substrates, including aromatic and aliphatic alkenes.
- Hasan, Kamrul,Brown, Nicole,Kozak, Christopher M.
-
experimental part
p. 1230 - 1237
(2011/06/27)
-
- Iron-catalyzed epoxidation of aromatic olefins and 1,3-dienes
-
The combination of iron(III) chloride, pyridine-2,6-dicarboxylic acid and formamidine ligands allows for the epoxidation of styrenes and conjugated dienes in excellent chemoselectivity and yields.
- Schroeder, Kristin,Enthaler, Stephan,Join, Benoit,Junge, Kathrin,Beller, Matthias
-
experimental part
p. 1771 - 1778
(2010/09/11)
-
- Design of a bio-inspired imidazole-based iron catalyst for epoxidation of olefins: Mechanistic insights
-
A novel defined iron catalyst for the epoxidation of aromatic and aliphatic olefins with hydrogen peroxide as the terminal oxidant is described. Our catalyst approach is based on bio-inspired both alkyl- and aryl-substituted imidazoles in combination with cheap and abundant iron trichloride hexahydrate. Heterocycles similar to imidazole can be used as ligands in this epoxidation system, too. The novel system is stable towards air and water. It is shown that the mechanism depends strongly on the used ligands and substrates. In the presence of radical scavengers no carbon-centered radical could be detected.
- Schr?der, Kristin,Junge, Kathrin,Spannenberg, Anke,Beller, Matthias
-
experimental part
p. 364 - 370
(2011/01/04)
-
- Easy access to α-bromoketones and epoxides from vic-dibromides under aqueous conditions
-
The conversion of vic-1,2 dibromides to α-bromoketones and epoxides using H2O2/dioxane and NaOH/water respectively under mild conditions has been described. Copyright Taylor & Francis Group, LLC.
- Patil, Rajendra D.,Adimurthy, Subbarayappa,Ranu, Brindaban C.
-
experimental part
p. 3233 - 3239
(2010/12/24)
-
- Homogeneous epoxidation of lipophilic alkenes by aqueous hydrogen peroxide: Catalysis of a Keggin-type phosphotungstate-functionalized ionic liquid in amphipathic ionic liquid solution
-
The ionic liquid compositions (ILC) composed of the Keggin-type phosphotungstate-functionalized ionic liquid of [Dopy]3[PW 12O40] (1) and the amphipathic IL mixture of [Bpy]BF 4 and [Dopy]BF4, were constructed as an effective catalytic system and ideal reaction medium for alkene epoxidation by aqueous H2O2, in which the real homogeneous catalysis was fulfilled with advantages of high activity, simplified work-up and available recyclability. The designing concept of the ILC and the IL effect on the activity/stability were discussed herein. The Royal Society of Chemistry 2009.
- Wang, Sa-Sa,Liu, Wei,Wan, Qing-Xia,Liu, Ye
-
scheme or table
p. 1589 - 1594
(2010/06/13)
-
- Synthesis of highly modular bis(oxazoline) ligands by Suzuki cross-coupling and evaluation as catalytic ligands
-
New bis(oxazoline) ligands (BOXs) containing biaryl substitutents at the C-4 position and H or CH2OR substituents at the C-5 position have been synthesized using Suzuki cross-coupling as the main tool for structural diversity. Copper, zinc, and
- Catto?n, Xavier,Pericàs, Miquel A.
-
experimental part
p. 8199 - 8205
(2009/12/24)
-
- 3-METHYL-2- ( (2S) -2- (4- (3-METHYL-L, 2, 4-0XADIAZ0L-5-YL) PHENYL) MORPHOLINO) -6- (PYRIMIDIN-4-YL) PYRIMIDIN-4 (3H) -ONE AS TAU PROTEIN KINASE INHIBITOR
-
A compound represented by the formula (I) or a pharmaceutically acceptable salt thereof: which is used for preventive and/or therapeutic treatment of a disease caused by abnormal activity of tau protein kinase 1 such as a neurodegenerative diseases (e.g.
- -
-
Page/Page column 28
(2009/04/25)
-
- 6-PYRIMIDINYL-PYRIMID-2-ONE DERIVATIVE
-
A compound represented by the formula (I) or a pharmaceutically acceptable salt thereof: which is used for preventive and/or therapeutic treatment of a disease caused by abnormal activity of tau protein kinase 1 such as a neurodegenerative diseases (e.g.
- -
-
Page/Page column 28-29
(2009/04/25)
-
- An ionic manganeseporphyrin catalyst for alkene epoxidations: The significant roles of the cationic trimethylbenzylammonium functionalities and the anionic mercaptopropionate counterions
-
An ionic manganeseporphyrin, bearing cationic trimethylbenzylammonium functionalities and mercaptopropionate [HS(CH2)2CO 2-] counteranions, was synthesized and applied as a catalyst for alkene epoxidations using iodosylbenzene (PhIO) as an oxidant. The reactions proceeded with high activity and oxide selectivity, and the catalyst exhibited relatively good recyclability. It was found that the presence of thiol (SH) group and quaternary ammonium substituents contributed greatly to the improved activity and stability of this ionic manganeseporphyrin. This was due to the synergistic effects of HS(CH2)2CO2 - as an axial ligand, and the suppression of oxidation degradation by the strongly electron-withdrawing nature of the quaternary ammonium cations. Georg Thieme Verlag Stuttgart.
- Cai, Yueqin,Lu, Yong,Liu, Ye,He, Ming-Yuan,Wan, Qingxia
-
p. 453 - 457
(2008/04/01)
-