- Kinetic resolution of racemic benzofused alcohols catalysed by HMFO variants in presence of natural deep eutectic solvents
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5-Hydroxymethylfurfural oxidase (HMFO) has demonstrated to be a useful biocatalyst for the selective oxidation of alcohols employing oxygen as mild oxidant with no requirement of expensive organic cofactors. This wild-type HMFO biocatalyst and an engineered thermostable variant have been tested in the kinetic resolution of different benzofused alcohols. The use of natural deep eutectic solvents was also explored in HMFO-catalysed oxidation of alcohols. The oxidation of racemic 1-indanol showed a higher conversion and selectivity in presence of 60% v/v of different NADES, especially for those containing carbohydrates. By choosing properly the biocatalyst and the NADES, good enantioselectivity values can be obtained, demonstrating the advantages of employing these neoteric solvents in biocatalysed processes.
- Fraaije, Marco,Lon?ar, Nikola,de Gonzalo, Gonzalo
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- Efficient acceptorless photo-dehydrogenation of alcohols and: N -heterocycles with binuclear platinum(ii) diphosphite complexes
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Although photoredox catalysis employing Ru(ii) and Ir(iii) complexes as photocatalysts has emerged as a versatile tool for oxidative C-H functionalization under mild conditions, the need for additional reagents acting as electron donor/scavenger for completing the catalytic cycle undermines the practicability of this approach. Herein we demonstrate that photo-induced oxidative C-H functionalization can be catalysed with high product yields under oxygen-free and acceptorless conditions via inner-sphere atom abstraction by binuclear platinum(ii) diphosphite complexes. Both alcohols (51 examples), particularly the aliphatic ones, and saturated N-heterocycles (24 examples) can be efficiently dehydrogenated under light irradiation at room temperature. Regeneration of the photocatalyst by means of reductive elimination of dihydrogen from the in situ formed platinum(iii)-hydride species represents an alternative paradigm to the current approach in photoredox catalysis.
- Zhong, Jian-Ji,To, Wai-Pong,Liu, Yungen,Lu, Wei,Che, Chi-Ming
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p. 4883 - 4889
(2019/05/16)
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- NEW COMPOUNDS SUITABLE AS CATALYSTS FOR POLYMERIZATION REACTIONS
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The invention relates to a compound of formula (I) and a process for synthesizing said compound. The invention further relates to the use of said compound as a catalyst, preferably for polymerization, such as, olefin polymerization. The invention also relates to the polymers produced using said catalyst and articles comprising said polymers.
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Page/Page column 71-72
(2019/04/10)
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- Metal-free oxidation of secondary benzylic alcohols using aqueous TBHP
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We report a simple, yet efficient metal-free oxidation of secondary benzylic alcohols in the presence of t-butyl hydroperoxide (70% TBHP) with high yields of up to 98%. This type of reaction can be carried out using a wide variety of substrates, requires no other organic solvent, and proves to be tolerant toward a variety of different functional groups.
- Wu, Jianglong,Liu, Yan,Ma, Xiaowei,Liu, Ping,Gu, Chengzhi,Dai, Bin
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supporting information
p. 1747 - 1758
(2016/10/30)
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- Highly enantioselective [3+2] coupling of cyclic enamides with quinone monoimines promoted by a chiral phosphoric acid
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Enantioselective [3+2] coupling of cyclic enamides with quinone monoimines was realised using a chiral phosphoric acid as a catalyst. This transformation allowed for the synthesis of highly enantioenriched polycyclic 2,3-dihydrobenzofurans (up to 99.9% ee). The absolute configuration of one product was determined by an X-ray crystal structural analysis. We also found a possible mechanism for this reaction.
- Zhang, Minmin,Yu, Shuowen,Hu, Fangzhi,Liao, Yijun,Liao, Lihua,Xu, Xiaoying,Yuan, Weicheng,Zhang, Xiaomei
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p. 8757 - 8760
(2016/07/15)
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- Functionalization of styrenes by copper-catalyzed borylation/ ortho-cyanation and silver-catalyzed annulation processes
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An efficient two-step method for the assembly of indanone derivatives starting from a simple vinyl arene has been developed. The sequence first involves addition of bis(pinacolato)diboron (B2pin2) and N-cyano-N-phenyl-p-methylbenzenesulfonamide (NCTS) to a broad range of styrenes by utilizing IMesCuCl as catalyst. This step simultaneously accomplishes hydroboration of the alkene and ortho cyanation of the benzene unit. The products thus obtained are further functionalized by a AgNO3/Selectfluor-mediated coupling of the BPin and cyano functionalities to annulate a new five-membered ring. This combined two-step sequence provides a versatile method for the site-selective derivatization of a broad range of vinyl arene substrates. A Cu and Ag sequence: The bis-functionalization of styrenes is accomplished through a copper-catalyzed process that enables hydroboration of the alkene and regioselective ortho cyanation of the arene. The resulting adducts are converted, by a radical cyclization process, into a cyclopentanone unit fused to the original aromatic ring. Together, these methods allow efficient cyclopentannulation of a broad range of styrene derivatives.
- Zhao, Wanxiang,Montgomery, John
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p. 12683 - 12686
(2015/10/28)
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- Rh-catalyzed reagent-free ring expansion of cyclobutenones and benzocyclobutenones
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Here we report a reagent-free rhodium-catalyzed ring-expansion reaction via C-C cleavage of cyclobutenones. A variety of poly-substituted cyclopentenones and 1-indanones can be synthesized from simple cyclobutenones and benzocyclobutenones. The reaction condition is near pH neutral without additional oxidants or reductants. The potential for developing a dynamic kinetic asymmetric transformation of this reaction has also been demonstrated. Further study supports the proposed pathway involving Rh-insertion into the cyclobutenone C-C bond, followed by β-hydrogen elimination, olefin insertion and reductive elimination.
- Chen, Peng-Hao,Sieber, Joshua,Senanayake, Chris H.,Dong, Guangbin
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p. 5440 - 5445
(2015/09/28)
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- Catalytic asymmetric cross-dehydrogenative coupling: Activation of C-H bonds by a cooperative bimetallic catalyst system
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A cooperative bimetallic catalyst system was applied in the catalytic asymmetric cross-dehydrogenative coupling of β-ketoesters and xanthene. Various optically active xanthene derivatives bearing a quaternary stereogenic carbon center were obtained in moderate to good yields (up to 90%) with excellent enantioselectivities (up to 99% ee). Meanwhile, a transition-state model was proposed to explain the origin of the asymmetric induction.
- Cao, Weidi,Liu, Xiaohua,Peng, Ruixue,He, Peng,Lin, Lili,Feng, Xiaoming
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supporting information
p. 3470 - 3472
(2013/05/23)
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- Preparation, physical properties and n-type FET characteristics of substituted diindenopyrazinediones and bis(dicyanomethylene) derivatives
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A series of halogen and alkyl substituted diindenopyrazinediones and bis(dicyanomethylene) derivatives have been synthesized as new n-type organic semiconductors based on nitrogen-containing heterocycles. Halogen groups were introduced to improve the electron injection. Their crystal structures and solid physical properties are discussed. Alkyl groups were introduced to increase the solubility in organic solvents. Furthermore, hexanoyl groups were introduced by oxidation of alkyl groups to increase the solubility and electron affinity. Dicyanomethylene groups were also introduced to further enhance the electron-accepting properties. Drop-cast as well as vapour deposited thin films showed n-type FET properties.
- Nishida, Jun-Ichi,Deno, Hironori,Ichimura, Satoru,Nakagawa, Tomohiro,Yamashita, Yoshiro
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experimental part
p. 4483 - 4490
(2012/07/28)
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- Efficient synthesis of halo indanones via chlorosulfonic acid mediated Friedel-Crafts cyclization of aryl propionic acids and their use in alkylation reactions
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Several halo indanones were synthesized from benzyl Meldrum's acid derivatives in two steps. Although several Lewis acids are effective for the Friedel-Crafts ring-closing reaction on more electron-rich arenes, in the case of the electron-deficient arenes this chemistry is not efficient. Here it is reported that chlorosulfonic acid (used as solvent) is an efficient reagent for cyclization of electron-withdrawing arenes. These molecules are potentially useful for subsequent alkylation reactions. The selective alkylation of 5,7-dibromo indanone is demonstrated using Pd-catalyzed Grignard coupling to provide monoalkylated indanone in good yield.
- Sharma, Anil K.,Subramani, Amutha V.,Gorman, Christopher B.
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p. 389 - 395
(2007/10/03)
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- Syntheses of compounds active toward glutamate receptors: II. Synthesis of spiro hydantoins of the indan series
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The article describes a general procedure for synthesizing hydantoins of the indan series, which makes it possible to obtain bioisosteric analogs of 1-aminoindan-1,5-dicarboxylic acid, a group I metabotropic glutamate receptor antagonist.
- Matveeva,Podrugina,Morozkina,Zefirova,Seregin,Bachurin,Pellicciari,Zefirov
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p. 1769 - 1774
(2007/10/03)
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- Synthesis of new C3h and C3v truxene derivatives
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Palladium-catalyzed cross coupling of 2,7,12-tribromotruxene with organostannanes and boronic acids leads to 2,7,12-trisubstituted truxenes. 5,10,15-Tdarylated and trialkynylated truxene derivatives are obtained by the reaction of truxenone with aryl Grignard reagents or an alkynyllithium, followed by reduction of the tertiary alcohols with Et3SiH or BF3. syn-5,10,15-Triarylated derivatives were obtained by the base-catalyzed isomerization of the anti derivatives.
- Go?mez-Lor, Berta,De Frutos, O?scar,Ceballos, Pla?cido A.,Granier, Thierry,Echavarren, Antonio M.
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p. 2107 - 2114
(2007/10/03)
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- Asymmetric strecker-type reaction of α-aryl ketones. Synthesis of (S)- αM4CPG, (S)-MPPG, (S)-AIDA, and (S)-APICA, the antagonists of metabotropic glutamate receptors
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Heating a mixture of α-aryl ketone with (R)-phenylglycinol produces a mixture of imine and 1,3-dioxazolidine. Treatment of this mixture with trimethylsilyl cyanide followed by transformation of nitrile to ester gives Strecker-type reaction products. The diastereoselectivity of the generated α-amino esters is from 2/1 to 7/1, and the (R,S)isomer is found as the major product. The (R,S) and (R,R)isomers can be separated by conversion to their N-Cbz or cyclization derivatives. Using this methodology, four antagonists of metabotropic glutamate receptors, (S)-αM4CPG, (S)-MPPG, (S)AIDA, and (S)- APICA, are synthesized.
- Ma, Dawei,Tian, Hongqi,Zou, Guixiang
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p. 120 - 125
(2007/10/03)
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- OXIME DERIVATIVES
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The invention concerns oxime derivatives of the formula I wherein R4 includes hydrogen, carboxy, carbamoyl, amino, cyano, trifluoromethyl, (1-4C)alkylamino, di(1-4C)alkylamino and (1-4C)alkyl; RS includes hydrogen, (1-4C)alkyl, (3-4C)alkeny1,(3-4C)alkynyl, (2-5C)alkanoyl, halogeno-(2-4-C)alkyl and hydroxy-(2-4C)alky1;Arl is phenylene or a hetercaryl diradical; Al is a direct link to XI, or Al is (1-4C)alkylene; XI is oxy, thio, sulphinyl or sulphonyl; Ar2 is phenylene or a heteroaryl diradical; RI is (1-4C)alkyl, (3-4C)alkenyl or (3-4C)alkyny1; and R2 and R3 together form a group of the formula -A2. X2-A3- which together with the carbon atom to which A2 and A3 are attached define a ring having 5 or 6 ring atoms, wherein each of A2 and A3 is (1-3C)alkylene and X2 is oxy, thio, sulphinyl, sulphonyl or imino; or a pharmaceutically-acceptable sah thereof; processes for their manufacture; pharmaceutical compositions containing them and their use as 5-lipoxygenase inhibitors.
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- Phenyl or bicyclo-alkenylfluoro amide pesticides
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Compound of the formula (I): or a salt thereof, wherein Q1 is a phenyl ring or a fused bicyclic ring system containing 9 or 10 ring carbon atoms at least one ring being aromatic, or Q1 is a dihalovinyl group; Q is an alkyl chain containing 1 to 12 carbon atoms and optionally containing one or two oxygen atoms and/or an unsaturated group --CR7 =CR8 --, or --C=C--, wherein R7 and R8 are selected from hydrogen or halo; a is 0 or 1; b is 0 or 1; the sum of a and b is 0 or 1; R2, R3, R4, R5 and R6 are the same or different, and are independently selected from hydrogen, halo and C1-4 alkyl; R1 is selected from hydrogen and C1-6 hydrocarbyl optionally substituted by dioxalanyl, halo, cyano, trifluoromethyl, trifluoromethylthio or C1-6 alkoxy are disclosed which have pesticidal activity. Pesticidal formulations containing the compounds of the formula (I), their use in the control of pests and methods for their preparation are also disclosed.
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- Pyrethrinoid esters carrying an indanyl nucleus and their use as pesticides
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Pyrenthrinoid esters with an indenyl nucleus having the following structural formula STR1 wherein the substituents are herein defined, have been shown to be useful as pesticides and in pesticidal compositions.
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- Hydrocarbures arylaliphatiques. Partie VII. Orientation dans la reaction de bromation de benzocyclenes bi- et tricycliques superieurs
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The bromination of 1,2,3-trimethylbenzene, and bi- and tricyclic fused ring systems (i.e. indan, tetralin, benzosuberan, 2a,3,4,5-tetrahydroacenaphthen and higher homologues) is described in this paper.This work is part of a research project studying the ring size influence of peri-fused semi-aromatic ring system on benzene reactivity.This study was started in a first step on acetylation and was continued on bromination.Forthcoming studies (now underway) concern the kinetic measurement of protodesilylation of univocal silyl derivatives.The synthesis of the starting bromo derivatives used for this latter study is described here.These bromides were used for the attribution via NMR spectroscopy of the electrophile reaction site in the direct bromination of the fused ring unsymmetrical systems (the reactive sites are obvious in symmetrical molecules). Thus, meta substitution is predominant in the case of tetraline and benzosuberan, but ortho substitution is relatively more important in tetralin.In 1,2,3-trimethylbenzene and the fused tricyclic compounds, substitution takes place in an ortho position respective to the substituent or the ring system, the meta position being totally deactivated.In the special case of a five-membered ring, the ortho position this ring is always non reactive.The reactivity differences between these compounds are explained by hyper conjugation and the stabilities of the transition states.
- Gruber, Rene,Cagniant, Denise,Cagniant, Paul
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