- Selective α-Deuteration of Cinnamonitriles using D2O as Deuterium Source
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The selective α-deuteration of α,β-unsaturated nitriles using the strong base tBuOK or a metal-ligand cooperative Ru pincer catalyst is described. With D2O as deuterium source and glyme as solvent at 70 °C, tBuOK is an efficient catalyst for deuteration at the α-C(sp2) position of cinnamonitriles, providing access to a broad range of deuterated derivatives in good to excellent yields and with very high levels of deuterium incorporation. While the tBuOK-catalysed protocol does not tolerate base-sensitive functional groups, cinnamonitrile derivatives containing a benzylic bromide or ester moiety were deuterated in excellent yields using Milstein's ruthenium PNN pincer catalyst. Moreover, the activity for H/D exchange of the metal-ligand cooperative Ru catalyst is found to be significantly higher than that of tBuOK, allowing reactions to proceed well even at room temperature. A mechanistic proposal is put forward that involves deprotonation of the cinnamonitrile α-CH position when using tBuOK as catalyst, whereas H/D exchange catalysis with the Ru PNN pincer likely proceeds via (reversible) oxa-Michael addition of D2O. (Figure presented.).
- Guo, Beibei,de Vries, Johannes G.,Otten, Edwin
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supporting information
p. 179 - 186
(2021/10/12)
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- One-Pot Synthesis of α,β-Unsaturated Esters, Ketones, and Nitriles from Alcohols and Phosphonium Salts
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A general method for the synthesis of α,β-unsaturated esters, ketones, and nitriles is successfully achieved by a one-pot copper-catalyzed oxidation with O 2 in air as oxidant. The solvent mixture of acetonitrile and formamide (1:1) is optimized to ensure the oxidation of alcohols, deprotonation of phosphonium salt, and Wittig reaction occur efficiently in one pot. A broad range of substrates has been explored for this process, including three electron-withdrawing group (CO 2 Et, COPh, CN) functionalized phosphonium salts. They reacted not only with benzylic and heteroaromatic alcohols, but also with aliphatic alcohols, forming the corresponding α,β-unsaturated esters, ketones, and nitriles in moderate to excellent yields.
- Ding, Weijie,Hu, Juan,Jin, Huile,Yu, Xiaochun,Wang, Shun
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p. 107 - 118
(2017/09/28)
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- Copper-catalyzed retro-aldol reaction of β-hydroxy ketones or nitriles with aldehydes: Chemo- and stereoselective access to (E)-enones and (E)-acrylonitriles
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A copper-catalyzed transfer aldol type reaction of β-hydroxy ketones or nitriles with aldehydes is reported, which enables chemo- and stereoselective access to (E)-α,β-unsaturated ketones and (E)-acrylonitriles. A key step of the in situ copper(i)-promoted retro-aldol reaction of β-hydroxy ketones or nitriles is proposed to generate a reactive Cu(i) enolate or cyanomethyl intermediate, which undergoes ensuing aldol condensation with aldehydes to deliver the products. This reaction uses 1.2 mol% Cu(IPr)Cl (IPr denotes 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) as the catalyst in the presence of 6.0 mol% NaOtBu cocatalyst at room temperature or 70 °C. A range of aryl and heteroaryl aldehydes as well as acrylaldehydes are compatible with many useful functional groups being tolerated. Under the mild and weakly basic conditions, competitive Cannizzaro-type reaction of benzaldehydes and side reactions of base-sensitive functional groups can be effectively suppressed, which show synthetic advantages of this reaction compared to classic aldol reactions. The synthetic potential of this reaction is further demonstrated by the one-step synthesis of biologically active quinolines and 1,8-naphthyridine in excellent yields (up to 91%). Finally, a full catalytic cycle for this reaction has been constructed using DFT computational studies in the context of a retro-aldol/aldol two-stage mechanism. A rather flat reaction energy profile is found indicating that both stages are kinetically facile, which is consistent with the mild reaction conditions.
- Zhang, Song-Lin,Deng, Zhu-Qin
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p. 7282 - 7294
(2016/08/05)
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- Dual [Fe+Phosphine] catalysis: Application in catalytic wittig olefination
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Iron hydride complexes of the general formula P2Fe(NO)CO)H are highly active catalysts for the hydrosilylation of aldehydes or ketones and phosphine oxides. Depending on the solvent, the in situ reduction of the phosphine oxide can be faster than the corresponding hydrosilylation of a carbonyl group. This unusual activity was used within the context of catalytic Wittig olefination. Picture perfect: Iron hydride complexes of the general formula P2Fe(NO)CO)H are highly active catalysts for the hydrosilylation of aldehydes or ketones and phosphine oxides. Depending on the solvent, the in situ reduction of the phosphine oxide can be faster than the corresponding hydrosilylation of a carbonyl group. This unusual activity is used within the context of catalytic Wittig olefination. EWG=Electron-withdrawing group.
- Rommel, Susanne,Belger, Christian,Begouin, Jeanne-Marie,Plietker, Bernd
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p. 1292 - 1301
(2015/04/27)
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- Copper-mediated transformation of organosilanes to nitriles with DMF and ammonium iodide
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Cyanation of aryl-, diaryldimethyl-, and styrylsilanes was developed for the first time under copper-mediated oxidative conditions using ammonium iodide and DMF as the combined source of nitrogen and carbon atom of the introduced cyano unit, respectively. The reaction was observed to proceed in a two-step process: initial conversion of organosilanes to their iodo intermediates and then cyanation. This method has a broad substrate scope with high functional group tolerance.
- Wang, Zhen,Chang, Sukbok
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p. 1990 - 1993
(2013/06/04)
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- 5, 7-SUBSTITUTED-IMIDAZO [1, 2-C] PYRIMIDINES AS INHIBITORS OF JAK KINASES
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Compounds of Formula I: (Formula should be inserted here) and stereoisomers and pharmaceutically acceptable salts and solvates thereof in which R1, R2, R3, R4, R5, R6, R7, X1 and X2 have the meanings given in the specification, are inhibitors of one or more JAK kinases and are useful in the treatment of autoimmune diseases, inflammatory diseases, rejection of transplanted organs, tissues and cells, as well as hematologic disorders and malignancies and their co-morbidities.
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Page/Page column 79
(2011/11/01)
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- Direct oxidative coupling of benzenes with acrylonitriles to cinnamonitriles catalyzed by Pd(OAc)2/HPMoV/O2 system
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A facile direct synthesis of cinnamonitriles from acrylonitriles and benzenes is successfully achieved by using Pd(OAc)2/HPMoV/O 2 catalyst system via the direct C-H bond activation of benzenes using molecular oxygen as a terminal oxidant.
- Obora, Yasushi,Okabe, Yoshihisa,Ishii, Yasutaka
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supporting information; experimental part
p. 4071 - 4073
(2010/11/04)
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- Synthesis and pharmacology of site-specific cocaine abuse treatment agents: 2-(Aminomethyl)-3-phenylbicyclo [2.2.2]- and - [2.2.1] alkane dopamine uptake inhibitors
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As part of a program to develop site-specific medications for cocaine abuse, a series of 2-(aminomethyl)-3-phenylbicyclo[2.2.2]- and -[2.2.1]alkane derivatives was synthesized and tested for inhibitory potency in [3H]WIN 35,428 binding and [3H]dopamine uptake assays using rat striatal tissue. Selected compounds were tested for their ability to substitute for cocaine in rat drug discrimination tests. Synthesis was accomplished by a series of Diels-Alder reactions, using cis- and trans-cinnamic acid derivatives (nitrile, acid, acid chloride) with cyclohexadiene and cyclopentadiene. Standard manipulations produced the aminomethyl side chain. Many of the compounds bound with high affinity (median IC50 = 223 nM) to the cocaine binding site as marked by [3H]WIN 35,428. Potency in the binding assay was strongly enhanced by chlorine atoms in the 3- and/or 4-position on the aromatic ring and was little affected by corresponding methoxy groups. In the [2.2.2] series there was little difference in potency between cis and trans compounds or between N,N-dimethylamines and primary amines. In the [2.2.1] series the trans exo compounds tended to be least potent against binding, whereas the cis exo compounds were the most potent (4-Cl cis exo: IC50 = 7.7 nM, 27-fold more potent than 4-Cl trans-exo). Although the potencies of the bicyclic derivatives in the binding and uptake assays were highly correlated, some of the compounds were 5-7-fold less potent at inhibiting [3H]-dopamine uptake than [3H]WIN 35,428 binding (for comparison, cocaine has a lower discrimination ratio (DR) of 2.5). The DR values were higher for almost all primary amines and for the trans-[2.2.2] series as compared to the cis-[2.2.2]. Most of the compounds had Hill coefficients approaching unity, except for the [2.2.2] 3,4-dichloro derivatives, which all had n(H) values of about 2.0. Two of the compounds were shown to fully substitute for cocaine in drug discrimination tests in rats, and one had a very long duration of action.
- Deutsch, Howard M.,Collard, David M.,Zhang, Liang,Burnham, Kikue S.,Deshpande, Abhay K.,Holtzman, Stephan G.,Schweri, Margaret M.
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p. 882 - 895
(2007/10/03)
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- STEREOSELECTIVE SYNTHESIS OF (2Z)-α,β-UNSATURATED NITRILES VIA TANDEM CONDENSATION-DESULFONYLATION OF α-CYANOSULFONES WITH ALDEHYDES
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In the presence of sodium telluride, α-cyanosulfones undergo tandem condensation-desulfonylation reaction with aromatic aldehydes to give (2Z)-α,β-unsaturated nitriles with good stereoselectivity.
- Huang, Xian,Pi, Jin-Hong,Huang, Zhi-Zhen
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p. 177 - 182
(2007/10/02)
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- Oxadiazole and oxadiazoline derivatives
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There are described new compounds of formula STR1 in which E is selected from the group consisting of residues of formula STR2 in which R" is selected from the group consisting of amino, vinyl, allyl, ethynyl, C1 -C5 alkyl, C1 -C5 alkoxy, or C1 -C5 alkylthio or a C1 -C5 alkyl group susbstituted by at least one halogen atom; and hydrogen; in which R1 and R2 are each selected from the group consisting of hydrogen, halogen, methyl and ethyl; and R' is selected from substituted phenyl when R" is other than hydrogen, and phenyl, thienyl and substituted phenyl and thienyl when R" is hydrogen. The compounds are useful in the control of parasites. Certain of the compounds have antimicrobial properties.
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