- Cyclohexeno[3,4]cyclodec-1,5-diyne-3-ene: A Convenient Enediyne
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Enediynes are widely studied to understand their cycloaromatization and the trapping of the resulting p-dehydrobenzene diradical. However, few model substrates are known, and they are hard to synthesize and difficult to handle. Herein we report cyclohexen
- Perrin, Charles L.,Shrinidhi, Annadka
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supporting information
p. 6911 - 6915
(2021/09/14)
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- Preparation method of heteroatom-containing cyclohexene halide
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The invention discloses a preparation method of a heteroatom-containing cyclohexene halide, belonging to the field of synthesis of fine chemical intermediates. According to the preparation method, cyclohexanone containing heteroatoms is used as a raw material, and gem-dihalide or alkenyl halide is mainly generated in a halogenating reagent; and after an additive is added into organic alkali, and hydrogen halide is removed to generate cyclohexene halide containing heteroatoms. The method is simple in process; the operation of purifying a mixture in traditional methods is avoided; and a productis fully utilized. Under close-to-elimination condition of gem-dibromide, an additive is added to overcome the problem of difficulties in gem-dichloride elimination is by adding, and the purpose of controlling regioselectivity is achieved through steric hindrance of different alkalis.
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Paragraph 0048-0050
(2019/12/25)
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- Synthesis of Vinyl Chlorides via Triphosgene-Pyridine Activation of Ketones
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Herein, we describe a mild method to prepare aliphatic and aromatic vinyl chlorides from their corresponding ketones via triphosgene-pyridine activation in dichloromethane at reflux. The mechanism of this reaction is proposed to involve formation of a put
- Saputra, Mirza A.,Ngo, Ly,Kartika, Rendy
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p. 8815 - 8820
(2015/09/15)
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- The continuous reaction device and method of using the continuous composite (by machine translation)
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PROBLEM TO BE SOLVED: compounds with high productivity can be generated. SOLUTION: 1 the raw material supply section 12 and a first, a second and 2 the raw material supply section 14, and a reaction part 18, the first reaction part 1 from the raw material supply section 1 and a second quantity of raw material, the raw material supply section 2 from the first reaction part 2 and a second quantity of raw material, the raw material supply section 1 from the first reaction part 1 and a second temperature of the raw material, the raw material supply section 2 from the first reaction part 2 and supplied to the temperature of the raw material, and having a control part 22, a continuous reaction device as shown in the drawing. Selected drawing: fig. 1 (by machine translation)
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Paragraph 0179
(2017/01/02)
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- Structure and Dynamic Features of an Intramolecular Frustrated Lewis Pair
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Di(mesityl)cyclohexenylphosphine undergoes hydroboration with Piers' borane [HB(C6F5)2] to yield the cyclohexylene- anellated frustrated Lewis pair 5. This P/B pair splits H2 with the formation of the product 4
- Axenov, Kirill V.,Moemming, Cornelia M.,Kehr, Gerald,Froehlich, Roland,Erker, Gerhard
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supporting information; experimental part
p. 14069 - 14073
(2011/02/23)
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- First catalytic and green synthesis of aryl-(Z)-vinyl chlorides and its plausible addition-elimination mechanism
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(Chemical Equation Presented) Via a catalytic cycle in the presence of scandium triflate (2 mol %)/DMF (1 mol %)/benzoyl chloride (5 mol %), aromatic ketones were treated with bis(trichloromethyl) carbonate (BTC) to afford aryl-(Z)-vinyl chlorides. All metal triflates tested in the reaction showed highly catalytic activity. A plausible addition-elimination mechanism was proposed. The present work describes the first catalytic and green route to the synthesis of aryl-(Z)-vinyl chlorides.
- Su, Weike,Jin, Can
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p. 993 - 996
(2007/10/03)
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- Method for chlorinating ketones
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In a process for chlorinating ketones which, apart from the carbonyl group, are inert in respect of triarylphosphine dichlorides, except for cyclopropyl methyl ketone, in which the ketones are reacted with a chlorinating agent in the presence of triarylphosphine oxides, the amount of triarylphosphine oxide is from 0.1 to 10 mol %, based on the amount of ketone. The ketones preferably have a least one CH-acid proton in the α position to the carbonyl group.
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- Dichotomous reactivity of PCl5 and PBr5 toward cyclic ketones: A one-step preparation of 1,1,2-trichlorocycloalkanes
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Small-ring cyclic ketones react with excess PCl5 in CCl4 (reflux, 1-3 d) to give the corresponding 1,1,2-trichlorocycloalkanes, but react with PBr5 to give ketones brominated in the α-positions.
- Brown,Chronister,Watkins,Mazzaccaro,Rajski,Fountain,McKay,Gibson
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p. 485 - 501
(2007/10/02)
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- One-pot synthesis of α-trimethylsilyl enones from vinylsilanes
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Photooxygenation of vinylsilanes in the presence of acetic anhydride and pyridine afforded α-trimethylsilyl enones 1 in moderate to good yields. Since the required starting materials are readily available, the present approach constitutes a useful alterna
- Adam,Richter
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p. 176 - 180
(2007/10/02)
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- THE REACTION OF DIALKYLTRICHLOROMETHYLPHOSPHINES WITH METHYL ISOCYANATE AND WITH SATURATED AND α,β-UNSATURATED CARBONYL COMPOUNDS
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Diethyltrichloromethylphosphine (4a) reacts with methyl isocyanate (6e) and with nonenolizable saturated aldehydes, 6b-c, to produce 1,2-λ5-oxaphosphetanes, 7b-e, whereas with enolizable saturated ketones, 6f,g, it gives mixtures of cycloaddition products, 7f,g, and vinyl chlorides, 14f,g.By treatment with 4a, 1,3-diketones 6h-j are exclusively transformed into vinyl chlorides, 14h-j. α,β-Unsaturated aldehydes, 6k,l, react with 4a to afford phosphine oxides 17k,l.The crucial role of the oxaphosphetane type intermediates, 15k,l, in the formation of 17k,l has been demonstrated. Key words: Diethyltrichloromethylphosphine; P-chlorodiethyldichloromethylenephosphorane; 1,2,λ5-oxaphosphetane; saturated and α,β-unsaturated carbonyl compounds; diethyl-(1,1-dichloroalkyl)phosphine oxides.
- Majewski, Piotr
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- Ring-fused and spiro cyclopentenones by Ni(CO)4-promoted intermolecular carbonylative cycloaddition of acetylenes with 3-halo- and 1-(halomethyl)cycloalkenes
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The title carbonylative cycloaddition of five- to eight-member ring 3-halo- and 1-(halomethyl)cycloalkenes with different acetylenes was studied. From moderate to good yields of ring-fused and spiro cyclopentenone derivatives were obtained, especially in the reaction with acetylenes bearing electron-withdrawing substituents by proper selection of the reaction conditions to avoid the acetylene polyinsertion and/or other side reactions from the organonickel intermediates. In this context, the beneficial role of acetate ion on the outcome of the reaction is rationalized. This process leading to the formation of bicycloadducts with the concomitant formation of up to six C-C bonds, with high regio- and stereoselectivity, can be useful in the synthesis of natural products as exemplified by the easy preparation of [5-5-5] tricyclic compound 14 from a 1:1 cis and trans isomeric mixture of 6-acetoxy-3-bromocyclooctene (11). A plausible general reaction mechanism is proposed that is consistent with all the products obtained.
- Pagès, Lluís,Llebaria, Amadeu,Camps, Francisco,Molins, Elies,Miravitlles, Caries,Moretó, Josep M.
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p. 10449 - 10461
(2007/10/02)
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- Reaction of alkylhypochlorites and xenon difluoride with cyclohexene
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Reactions of alkylhypochlorites and xenon difluoride with cyclohexene give primarily 1-chloro-2-fluorocyclohexanes via formation of a complex between xenon difluoride and the alkylhypochlorite.
- Shellhamer,Horney,Toth,Heasley
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p. 6903 - 6906
(2007/10/02)
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- SYNTHESIS OF PYRIMIDINES FROM VINYL CHLORIDES AND NITRILES BY THE RITTER REACTION
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Chloroalkenes with a chlorine atom at the vinylic position and also phenylacetylene react with nitriles in the presence of trifluoromethanesulfonic acid to form tri- and tetrasubstituted pyrimidines.
- Borodaev, S. V.,Zubkova, O. V.,Luk'yanov, S. M.
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p. 2100 - 2103
(2007/10/02)
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- PREPARATION OF POLYHALOGENOCYCLOPROPANES BY ADDITION OF HALOGENOCARBENES TO HALOGENO-ALKENES UNDER PHASE TRANSFER CONDITIONS
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A range of 1-halogenocycloalkenes, 2-halogeno-alkenes, and 1-halogeno- and 1,1-dihalogeno-2-methylprop-1-enes are converted to polyhalogenocyclopropanes by reaction with dichloro- or dibromocarbenes, generated from the haloform and aqueous base in the pre
- Baird, Mark. S.,Nethercott, William,Slowey, Paul D.
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p. 3815 - 3829
(2007/10/02)
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- Lewis Acid Catalysis of Ene Addition of Chloral and Bromal to Olefins; Product Studies
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The addition of chloral and bromal to a variety of alkyl-substituted alkenes has been investigated.The effect of the reaction of varying the Lewis acid catalyst and the structure of substrate have been studied.Anhydrous AlCl3 was found to be most effective catalyst, and ene-type adducts were the major products in most cases.Side reactions were observed with the less reactive systems leading, variously, to the formation of trihalogenoketones, hydrohalogenated ene adducts, and cyclic ethers.Conditions for optimising the yield of ene adducts were established in some cases.The trihalogenoketone by-products can be conveniently removed by a Grignard-type reaction.
- Benner, Jill P.,Gill, G. Bryon,Parrott, Stephen J.,Wallace, Brian
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p. 291 - 313
(2007/10/02)
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- A DIRECT SYNTHESIS OF 1-CYCLOALKENYLPHOSPHONATES
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A series of 1-cycloalkenylphosphonoate diesters has been synthesized starting with the corresponding vinylic chlorides.This has been accomplished using the Cu(I) complexes of triethyl phosphite in a direct reaction with the vinylic chlorides.This represen
- Banerjee, Shyamal,Engel, Robert,Axelrad, George
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- COMPARISON OF SYN DEHYDROHALOGENATIONS FROM TANS-1-BROMO-2-CHLOROCYCLOALKENES PROMOTED BY COMPLEX BASE AND BY POTASSIUM TERT-BUTOXIDE
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Compared with t-BuOK-t-BuOH, syn eliminations from trans-1-bromo-2-chlorocycloalkanes (C4-C8) induced by NaNH2-NaO-t-Bu in THF are rapid, exhibit greater propensity for dehydrochlorination and show little sensitivity to ring size of the dihalocycloalkane.
- Croft, Alan P.,Bartsch, Richard A.
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p. 2737 - 2740
(2007/10/02)
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- Complex-Base-Promoted Syn Eliminations from trans-1-Bromo-2-chlorocyclohexane
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Syn eliminations from trans-1-bromo-2-chlorocyclohexane (1) induced by complex-base combinations of NaNH2-NaOR(Ar) in tetrahydrofuran at room temperature favor dehydrochlorination (54-65percent) over dehydrobromination.Under the heterogeneous reaction conditions, oxyanion bases derived from tertiary, secondary, and branched primary alcohols as well as phenols and 2-butanone are effective complex-base components, which suggests that NaNH2 is the effective base species.Reactions of 1 with NaNH2-Na-t-Bu are not influenced by ultrasonic irradiation, but the propensity for lossof the normally poorer leaving group disappears in the presence of 15-crown-5.Transition states for complex-base-promoted syn eliminations are discussed.
- Croft, Alan P.,Bartsch, Richard A.
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p. 876 - 879
(2007/10/02)
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- Photochemistry of Alkyl Halides. 10. Vinyl Halides and Vinylidene Dihalides
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The photobehavior of the acyclic vinyl iodide 2, the 1-iodocycloalkenes 11-14 and 39, the (halomethylene)cycloalkanes 45-48, and the (dihalomethylene)cyclohexanes 62-64 has been studied.Except for the dichloride 64, which exhibited only radical behavior, each of the halides afforded a mixture of ionic and radical products.The two bromides studied, 48 and 63, afforded lower ratios of ionic to radical products than the corresponding iodides 45 and 62.Irradiation of vinyl iodides was found to be a convenient and powerful method for the generation of vinyl cations, including the highly strained 1-cyclohexenyl and 1-cyclopentenyl cations and the unstabilized α-unsubstituted cations 51 and 54.The latter cations underwent rearrangement to the ring-expanded 1-cycloalkenyl cations 28 and 36, respectively.Lowering the temperature of the irradiation of iodides 13, 14, and 45 resulted in an increased ratio of ionic to radical products.However, iodide 47, which underwent principally fragmentation to enyne 61, showed little temperature effect.
- Kropp, Paul J.,McNeely, Steven A.,Davis, Robert Drummond
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p. 6907 - 6915
(2007/10/02)
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- Synthetic Applications of Conjugated Azocarbinols. Radical Chain Hydrophenylation and Hydrocyclohexenylation of Haloethenes
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2-(Phenylazo)-2-propanol (5) and (phenylazo)diphenylmethanol (6) decompose in solution by process involving phenyl radicals.Similarly, 1-(1-azocyclohexenyl)cyclohexanol (7) decomposes to generate the 1-cyclohexenyl radical.Evidence for radical intermediates includes the formation of chlorobenzene and 1-chlorocyclohexene, respectively, from decomposition of 5 (or 6) and 7 in CCl4.Evidence for induced, chain decomposition by radical abstraction of hydroxyl hydrogen, in concert with breaking of at least one C-N bond of the azo function, includes faster decomposition in CCl4 than in benzene, acceleration of decomposition in CCl4 by thiophenol, and acceleration of decomposition in benzene by trityl radicals.That decomposition mechanism is supported also by the finding that methyl ethers and acetate esters of the azoalcohols decompose much more slowly than the alcohols themselves.Phenyl radicals from either 5 or 6, and 1-cyclohexenyl radicals from 7, can be trapped with some alkene by addition.Such radical adducts subsequently pick up a hydrogen atom, presumably by abstracting from the hydroxyl group of the azocarbinol in concert with C-N bond breaking.The overall processes, then, are hydrophenylation of alkenes with 5 and 6 and hydro-1-cyclohexenylation of alkenes with 7 by a radical chain mechanism.The processes are of preparative value only in cases of alkene substrates which are neither highly polymerizable nor prone to radical attack on allylic substituents.Several highly halogenated compounds prepared by treatment of haloethenes with 6 or 7 are reported.The reaction between 5 and benzaldehyde, to form acetone and 1-benzoyl-2-phenylhydrazine, was found to be second order overall, first order in 5 and first order in benzaldehyde between 0.4 M and neat benzaldehyde.This result does not appear to be compatible with a mechanism involving decomposition of 5 to acetone and phenyldiazene, with subsequent reaction of the latter with benzaldehyde.
- Chang, Yau-Min,Profetto, Ralph,Warkentin, John
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p. 7189 - 7195
(2007/10/02)
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