3591-42-2Relevant academic research and scientific papers
Synthesis of gem-Dichlorocyclopropanes Using Liquid–Liquid Slug Flow
Lee, Jong Won,Jang, Yea Seul,Park, Jong Min,Park, Chan Pil
supporting information, p. 1089 - 1092 (2021/06/23)
By analyzing the causes of precipitation and clogging in continuous flow dichlorocyclopropanation, we established that the flow reaction can be performed only with T-junctions and microtubes. Unlike tertiary amines, when quaternary ammonium salts were used as PTCs, precipitation and clogging in microchannels did not occur, and an excellent yield of up to 99% was obtained after optimizing the reaction temperature, reactant concentration, and retention time. In the scale-up experiment, the reaction yields slightly decreased as the inner diameter (ID) of the microchannel was increased, but the calculated throughput increased from 2.41 g/h (ID: 1.5 mm) to 3.46 g/h (ID: 1.9 mm) and 5.13 g/h (ID: 2.4 mm).
KOtBu as a single electron donor? Revisiting the halogenation of alkanes with CBr4 and CCl4
Emery, Katie J.,Young, Allan,Arokianathar, J. Norman,Tuttle, Tell,Murphy, John A.
, (2018/05/22)
The search for reactions where KOtBu and other tert-alkoxides might behave as single electron donors led us to explore their reactions with tetrahalomethanes, CX4, in the presence of adamantane. We recently reported the halogenation of adamantane under these conditions. These reactions appeared to mirror the analogous known reaction of NaOH with CBr4 under phase-transfer conditions, where initiation features single electron transfer from a hydroxide ion to CBr4. We now report evidence from experimental and computational studies that KOtBu and other alkoxide reagents do not go through an analogous electron transfer. Rather, the alkoxides form hypohalites upon reacting with CBr4 or CCl4, and homolytic decomposition of appropriate hypohalites initiates the halogenation of adamantane.
Is a phase transfer catalyst really needed for gem-dihalocyclopropanation of alkenes with haloforms in the presence of alkali metal hydroxide?
Karwowska,Jonczyk
, p. 45 - 49 (2008/02/11)
Chloroform, bromoform and dibromochloromethane react with alkenes in the presence of cone. aq. sodium hydroxide, without phase-transfer catalyst, giving gem-dihalocyclopropanes. The process is particularly useful for preparation of gem-bromochlorocyclopropanes which are formed in good yields and in high selectivity.
New multi-site phase transfer catalyst for the addition of dichlorocarbene to olefins
Shanmugan,Balakrishnan
, p. 1069 - 1074 (2008/02/11)
Three step synthesis of a new, water-soluble multi-site phase transfer catalyst (MPTC-I), viz., α,α1,α11- tris(triethyl ammonium methylene bromide) β-hydroxy ethyl benzene is described. The potentiality of MPTC-I is demonstrated by studying kinetic aspects of the reactions, viz. dichlorocarbene addition to styrene, α-methyl styrene and trans-stilbene.
gem-Dihalocyclopropane formation by iron/copper activation of tetrahalomethanes in the presence of nucleophilic olefins. Evidence for a carbene pathway
Léonel, Eric,Lejaye, Michael,Oudeyer, Sylvain,Paugam, Jean Paul,Nédélec, Jean-Yves
, p. 2635 - 2638 (2007/10/03)
The activation of CBr4 and CCl4 by a bimetallic iron/copper couple in acetonitrile is a new, inexpensive, nontoxic and efficient procedure for gem-dibromo- and gem-dichloromethylenation of nucleophilic alkenes. This new route to gem-dihalocyclopropanes involves dihalocarbene species.
Formation of gem-Dichlorocyclopropanes from Perhalomethanes and Alkenes in a Phase-Transfer Catalytic (PTC) System
Fedorynski, Michal,Dziklinska, Anna,Jonczyk, Andrzej
, p. 297 - 298 (2007/10/02)
Perhalomethanes YCCl3 (Y = Cl, Br) react with alkenes in the phase-transfer catalytic system to give gem-dichlorocyclopropanes.
DIHALOMETHANES AS C-H ACIDS IN THE CATALYTIC TWO-PHASE (CTP) SYSTEM - A NEW METHOD FOR THE SYNTHESIS OF gem-DICHLOROCYCLOPROPANES
Jonczyk, A.,Balcerzak, P.
, p. 4697 - 4700 (2007/10/02)
Dihalomethanes react with carbon tetrachloride and alkenes in the CTP system affording gem-dichlorocyclopropanes.
A CONVENIENT METHOD FOR SYNTHESIS OF GEM-BROMOCHLOROCYCLOPROPANES
Xu, Linxiao,Tao, Fenggang
, p. 2117 - 2122 (2007/10/02)
Gem-bromochlorocyclopropanes can be prepared by a convenient method based on the reactions of the mixtures of haloforms and tetrahalomethanes or hexahaloethane with powdered sodium hydroxide.
Kinetics of Cyclopropyl Radical Reactions. 2. Studies on the Inversion of Cyclopropyl and 1-Methylcyclopropyl Radicals and on the Kinetics of Some Addition and Abstraction Reactions of 1-Methylcyclopropyl and 1-Methoxycyclopropyl Radicals
Johnston, Linda J.,Ingold, K. U.
, p. 2343 - 2348 (2007/10/02)
Laser flash photolytic studies have shown that the 1-methylcyclopropyl radical has a reactivity similar to that of the cyclopropyl radical toward styrene, β-methylstyrene, 1,4-cyclohexadiene, CCl3Br, and n-Bu3SnH but that it is more reactive toward CCl4.Chemical trapping with CCl3Br of these two radicals stereospecifically labeled with deuterium yields rate constants for their inversion at 71 deg C of (2.1 +/- 0.8) * 1011 s-1 for c-C3H4.CH3 and ca. 1012 s-1 for c-C3H5..EPR spectra of 13C-labeled radicals confirm that they are nonplanar: a13Cα = 98 and 95.9 G for c-C3H4.CH3 and c-C3H5., respectively.The similar magnitudes of these splittings implies that there is also a similar degree of deviation from planarity.The barrier to inversion is probably ca. 3 kcal/mol for both radicals but the c-C3H5. inverts more rapidly possibly because of hydrogen tunneling. 1-Methoxycyclopropyl is less reactive toward styrene and 1,4-cyclohexadiene than the other two radicals.The EPR spectrum of this radical could not be obtained.
Carbon Tetrachloride-Dimethyl Sulphone-Potassium Hydroxide-t-Butyl Alcohol: a Convenient New Reagent for gem-Dichloromethylenation of Alkenes
Poon, Chi-Duen,Yuen, Po-Wai,Man, Tim-On,Li, Chun-Sing,Chan, Tze-Lock
, p. 1561 - 1563 (2007/10/02)
The action of dimethyl sulphone-potassium hydroxide-t-butyl alcohol on carbon tetrachloride readily affords dichlorocarbene.In the presence of alkenes, gem-dichlorocyclopropanes are formed in moderate to high yields.The dichlorocarbene generated by this procedure adds stereospecifically to alkenes with retention of geometric configuration about the carbon-carbon double bond.Relative reactivities of alkenes towards the CCl4-derived dichlorocarbene parallel the nucleophilicities of the alkenes and indicate that free dichlorocarbene is probably involved.
