- Photoenzymatic Synthesis of α-Tertiary Amines by Engineered Flavin-Dependent "ene"-Reductases
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α-Tertiary amines are a common motif in pharmaceutically important molecules but are challenging to prepare using asymmetric catalysis. Here, we demonstrate engineered flavin-dependent ‘ene'-reductases (EREDs) can catalyze radical additions into oximes to prepare this motif. Two different EREDs were evolved into competent catalysts for this transformation with high levels of stereoselectivity. Mechanistic studies indicate that the oxime contributes to the enzyme templated charge-transfer complex formed between the substrate and cofactor. These products can be further derivatized to prepare a variety of motifs, highlighting the versatility of ERED photoenzymatic catalysis for organic synthesis.
- Gao, Xin,Turek-Herman, Joshua R.,Choi, Young Joo,Cohen, Ryan D.,Hyster, Todd K.
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supporting information
p. 19643 - 19647
(2021/12/01)
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- Synthesis and reactivity of α-sulfenyl-β-chloroenones, including oxidation and Stille cross-coupling to form chalcone derivatives
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The synthesis of a range of novel α-sulfenyl-β-chloroenones from the corresponding α-sulfenylketones, via a NCS mediated chlorination cascade, is described. The scope of the reaction has been investigated and compounds bearing alkyl- and arylthio substituents have been synthesised. In most instances, the Z α-sulfenyl-β-chloroenones were formed as the major products, while variation of the substituent at the β-carbon position led to an alteration in stereoselectivity. Stille cross-coupling with the Z α-sulfenyl-β-chloroenones led to selective formation of Z sulfenyl chalcones, while the E α-sulfenyl-β-chloroenones did not react under the same conditions. Oxidation of the Z α-sulfenyl-β-chloroenones was followed by isomerisation, leading to the E α-sulfinyl-β-chloroenones. Stille cross-coupling with the E α-sulfinyl-β-chloroenones produced the E sulfinyl chalcones. Either the E or Z sulfinyl chalcones can be obtained by altering the sequence of oxidation and Stille cross-coupling.
- Kearney, Aoife M.,Murphy, Linda,Murphy, Chloe C.,Eccles, Kevin S.,Lawrence, Simon E.,Collins, Stuart G.,Maguire, Anita R.
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supporting information
(2021/05/04)
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- Palladium-Catalyzed C–C Ring Closure in α-Chloromethylimines: Synthesis of 1H-Indoles
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The C-C ring closure of α-chloromethyl alkyl or aryl N-aryl imines catalyzed with 1 to 10 % Pd(OAc)2/P(p-tolyl)3 afford efficiently 2-aryl- and 2-alkyl-1H-indoles. The heterocyclization reaction involves the initial formation of [2-(arylimino)ethyl]palladium(II) chloride complexes with subsequent C-H activation of the aromatic amine ring. Readily or commercially available α-chloromethyl-aryl or -alkyl ketones are used as the precursors. Functionalized indoles at the benzene ring are obtained when the imines are derived from substituted anilines.
- Bellezza, Delia,Noverges, Bárbara,Fasano, Francesco,Sarmiento, Jeymy T.,Medio-Simón, Mercedes,Asensio, Gregorio
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p. 1229 - 1235
(2019/01/04)
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- A Simple and Efficient Method for the Preparation of α-Halogenated Ketones Using Iron(III) Chloride and Iron(III) Bromide as Halogen Sources with Phenyliodonium Diacetate as Oxidant
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α-Halogenated ketones are both unique structure moieties existing in biologically natural products and valuable synthetic intermediates for the preparation of functional molecules. An efficient and scalable method for the preparation of α-halogenated ketone using iron (III) chloride and iron (III) bromide as halogen sources with phenyliodonium diacetate as oxidant has been developed, featuring mild reaction conditions, environmentally friendly reagents, and wide substrate scope. Notably, the three-step synthesis of drug prasugrel was achieved using this developed method as a key step with 30% yield on gram-scale. Additionally, the reaction mechanism involving chloride cation was proposed based on some preliminary control experiments. (Figure presented.).
- Tang, Shi-Zhong,Zhao, Wenshuang,Chen, Tao,Liu, Yang,Zhang, Xiao-Ming,Zhang, Fu-Min
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supporting information
p. 4177 - 4183
(2017/12/18)
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- Direct conversion of alcohols to α-chloro aldehydes and α-chloro ketones
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Direct conversion of primary and secondary alcohols into the corresponding α-chloro aldehydes and α-chloro ketones using trichloroisocyanuric acid, serving both as stoichiometric oxidant and α-halogenating reagent, is reported. For primary alcohols, TEMPO has to be added as an oxidation catalyst, and for the transformation of secondary alcohols (TEMPO-free protocol), MeOH as an additive is essential to promote chlorination of the intermediary ketones.
- Jing, Yuanyuan,Daniliuc, Constantin G.,Studer, Armido
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supporting information
p. 4932 - 4935
(2015/04/27)
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- Electrophilicity of α-oxo gold carbene intermediates: Halogen abstractions from halogenated solvents leading to the formation of chloro/bromomethyl ketones
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α-Oxo gold carbenes generated via intermolecular oxidation of terminal alkynes are shown to be highly electrophilic and can effectively abstract halogen from halogenated solvents such as 1,2-dichloroethane or 1,2-dibromoethane. Chloro/bromomethyl ketones are prepared in moderate efficiencies in one step using Ph3PAuNTf2 as the catalyst and 8-methylquinoline N-oxide as the oxidant.
- He, Weimin,Xie, Longyong,Xu, Yingying,Xiang, Jiannan,Zhang, Liming
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supporting information; experimental part
p. 3168 - 3171
(2012/06/01)
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- Copper(I)-promoted synthesis of chloromethyl ketones from trichloromethyl carbinols
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(Chemical Equation Presented) Reaction of several trichloromethyl carbinols with 2 equiv of CuCl/bpy in refluxing DCE for 3 h afforded chloromethyl ketones in excellent yield by 1,2-H shift in the copper-chlorocarbenoid intermediate.
- Ram, Ram N.,Manoj
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p. 5633 - 5635
(2008/12/21)
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- Methods and Compositions for Treatment of Scleritis and Related Disorders
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The present teachings relate to the field of anti-inflammatory substances and more particularly to compounds that are useful for the treatment of scleritis, a scleritis symptom, or a scleritis-related disorder. In one aspect, methods of treating scleritis, a scleritis symptom, or a scleritis-related disorder generally include administering to a subject a compound of Formula I: or a pharmaceutically acceptable salt, hydrate or ester thereof, wherein W1, W2, R1, L, X, Y, Z, and n1 are defined as described herein.
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Page/Page column 30-31
(2008/12/05)
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- Studies on the chemistry and reactivity of α-substituted ketones in isonitrile-based multicomponent reactions
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(Chemical Equation Presented) Using the Passerini and Ugi reactions as representative tests, the utility of several α-substituted ketones R-CO-CH2-X (X = sulfonyloxy, acyloxy, azido, halo, hydroxy, and sulfonyl) in isonitrile-based multicompone
- Fan, Lijun,Adams, Ashley M.,Polisar, Jason G.,Ganem, Bruce
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body text
p. 9720 - 9726
(2009/04/07)
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- 2-(4-Chlorobenzyl)-3-hydroxy-7,8,9,10-tetrahydrobenzo[H] quinoline-4-carboxylic acid (PSI-697): Identification of a clinical candidate from the quinoline salicylic acid series of P-selectin antagonists
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P-selectin-PSGL-1 interaction causes rolling of leukocytes on the endothelial cell surface, which subsequently leads to firm adherence and leukocyte transmigration through the vessel wall into the surrounding tissues. P-selectin is upregulated on the surface of both platelets and endothelium in a variety of atherosclerosis-associated conditions. Consequently, inhibition of this interaction by means of a small molecule P-selectin antagonist is an attractive strategy for the treatment of atherosclerosis. High-throughput screening and subsequent analoging had led to the identification of compound 1 as the lead candidate. Herein, we report the continuation of this work and the discovery of a second-generation series, the tetrahydrobenzoquinoline salicylic acids. These compounds have improved pharmacokinetic properties, and a number of them have shown oral efficacy in mouse and rat models of atherogenesis and vascular injury. The lead 31 (PSI-697), is currently in clinical development for the treatment of atherothrombotic vascular events.
- Kaila, Neelu,Janz, Kristin,Huang, Adrian,Moretto, Alessandro,DeBernardo, Silvano,Bedard, Patricia W.,Tam, Steve,Clerin, Valerie,Keith Jr., James C.,Tsao, Desirée H.H.,Sushkova, Natalia,Shaw, Gray D.,Camphausen, Raymond T.,Schaub, Robert G.,Wang, Qin
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- A mechanistic study of the chromium(II)-mediated transformations of trichloromethyl alkyls and carbinols: evidence for carbene, carbyne, and carbenoid intermediates
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Using CrCl2 in THF at room temperature, trichloromethyl carbinols and trichloromethylalkanes are readily transformed to the highly reactive α-chlorocarbenes, carbynes and α-chloro-α-chromium(III) vinylidene carbenoids. A mechanistic study is carried out to determine the nature of the intermediates.
- Bejot, Romain,Tisserand, Steve,Li, De Run,Falck,Mioskowski, Charles
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p. 3855 - 3858
(2008/02/02)
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- Methods and compositions for selectin inhibition
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The present invention relates to the field of anti-inflammatory substances, and more particularly to novel compounds that act as antagonists of the mammalian adhesion proteins known as selectins. In some embodiments, methods for treating selectin mediated disorders are provided which include administration of compound of Formula I: wherein the constituent variables are defined herein.
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Page/Page column 30
(2008/06/13)
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- HISTONE DEACETYLASE INHIBITORS BASED ON ALPHACHALCOGENMETHYLCARBONYL COMPOUNDS
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Histone deacetylase is a metallo-enzyme with zinc at the active site. Compounds having a zinc-binding moiety, for example, an alpha-chalcogenmethylcarbonyl group, such as an alpha-ketothio group, can inhibit histone deacetylase. Histone deacetylase inhibition can repress gene expression, including expression of genes related to tumor suppression. Accordingly, inhibition of histone deacetylase can provide an alternate route for treating cancer, hematological disorders, e.g., hemoglobinopathies, autosomal dominant disorders, e.g. spinal muscular atrophy and Huntington’s disease, genetic related metabolic disorders, e.g., cystic fibrosis and adrenoleukodystrophy, or for stimulating hematopoietic cells ex vivo.
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Page column 18
(2008/06/13)
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- Preparation of 1-aminoalkylphosphonic acids and 2-aminoalkylphosphonic acids by reductive amination of oxoalkylphosphonates
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By reacting dialkyl 1-oxo- or 2-oxoalkylphosphonates with benzhydrylamine followed by reduction with triacetoxyborohydride and acid hydrolysis gave corresponding aminoalkylphosphonic acids with satisfactory yields. The use of benzylamine, α-methylbenzylamine and tritylamine was unsuccessful in the case of dialkyl 1-oxoalkylphosphonates whereas conversion of 2-oxoalkylphosphonates was also achieved although with lower yields.
- Ryglowski, Artur,Kafarski, Pawel
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p. 10685 - 10692
(2007/10/03)
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- Ligand Exchange Reaction of Sulfoxides in Organic Synthesis: A New Synthesis of α-Chloroketones from Carbonyl Compounds with One-Carbon Homologation
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A new procedure for one-carbon homologation of carbonyl compounds to α-chloroketones is described.Addition of the carbanion of dichloromethyl phenyl sulfoxide with ketones and aldehydes gave the adducts, chloro alcohols, in good yields.Treatment of the chloro alcohols with EtMgBr or lithium diisopropylamide gave one-carbon homologated α-chloroketones via β-oxido carbenoid rearrangement in moderate to good yields.One-carbon homologation of esters to α-chloroketones was realized via the ligand exchange reaction of the sulfinyl group of α-chloro α-sulfinyl ketones, which were synthesized from methyl esters and chloromethyl phenyl sulfoxide, with EtMgBr.
- Satoh Tsuyoshi,Mizu, Yasuhiro,Kawashima, Taku,Yamakawa, Koji
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p. 703 - 710
(2007/10/02)
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- Preparation of 1,4-Dienes from 2-(2-Hydroxyalkylseleno)benzothiazoles by the Reaction Involving Se -> O Azaaromatic Ring Rearrangement
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The reactions of 2-(2-oxoalkylseleno)benzothiazoles with allylic Grignard reagents in the presence of BF3*OEt2 gave the corresponding 2-benzothiazoles which, on treatment with Ph3P and NaH, afforded 1,4-dienes in good to excellent yields.
- Shibata, Koichi,Mitsunobu, Oyo
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p. 3163 - 3173
(2007/10/02)
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- Dioxalane containing imidazole compounds, compositions and use
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Compounds useful as antifungal, antibacterial and antiprotozoal agents are represented by the formula: STR1 wherein: Z is oxygen or sulfur; R1 is phenyl optionally substituted with one or more substituents selected from the group consisting of halo, lower alkyl of one to four carbon atoms, lower alkoxy of one to four carbon atoms and trifluoromethyl; R2 is phenyl or benzyl wherein the phenyl ring of R2 is optionally substituted by one or more substituents selected from the group consisting of halo, lower alkyl of one to four carbon atoms, lower alkoxy of one to four carbon atoms and trifluoromethyl; or by a phenyl optionally substituted by halo, lower alkyl of one to four carbon atoms, lower alkoxy of one to four carbon atoms or trifluoromethyl; and the antimicrobial acid addition salts thereof.
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- NOVEL SELECTIVE SYNTHESIS OF α-CHLOROMETHYL, α,α-DICHLOROMETHYL, AND α,α,α-TRICHLOROMETHYL KETONES FROM ALDEHYDE UTILIZING ELECTROREDUCTION AS KEY REACTIONS
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A variety of α-chloromethyl, α,α-dichloromethyl, and α,α,α-trichloromethyl ketones were synthesized from aldehyde utilizing cathodic reduction as key reactions.
- Shono, Tatsuya,Kise, Naoki,Yamazaki, Akira,Ohmizu, Hiroshi
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p. 1609 - 1612
(2007/10/02)
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