4541-85-9Relevant academic research and scientific papers
Metal-free transfer hydrochlorination of internal C-C triple bonds with a bicyclo[3.1.0]hexane-based surrogate releasing two molecules of hydrogen chloride
Oestreich, Martin,Weidkamp, Andreas J.
supporting information, p. 973 - 976 (2022/02/01)
The development and application of a transfer hydrochlorination reagent based on a trichlorinated bicyclo[3.1.0]hexane core that transfers two molecules of HCl per molecule of surrogate to a π-basic substrate under B(C6F5)3 catalysis is reported. Lewis acid-assisted chloride abstraction followed by thermal electrocyclic cyclopropyl-to-allyl cation ring opening releases ring strain as a previously unexploited driving force.
Iodine(III)-Mediated Oxidative Hydrolysis of Haloalkenes: Access to α-Halo Ketones by a Release-and-Catch Mechanism
Jobin-Des Lauriers, Antoine,Legault, Claude Y.
supporting information, p. 108 - 111 (2016/01/15)
An unprecedented iodine(III)-mediated oxidative transposition of vinyl halides has been accomplished. The products obtained, α-halo ketones, are useful and polyvalent synthetic precursors. There are only a handful of reported examples of the direct conversion of vinyl halides to their corresponding α-halo carbonyl compounds. Insights into the mechanism and demonstration that this synthetic transformation can be done under enantioselective conditions are reported.
A mild synthesis of vinyl halides and gem-dihalides using triphenyl phosphite-halogen-based reagents
Spaggiari, Alberto,Vaccari, Daniele,Davoli, Paolo,Torre, Giovanni,Prati, Fabio
, p. 2216 - 2219 (2007/10/03)
A new application of (PhO)3P-halogen-based reagents to the synthesis of vinyl halides and gem-dihalides is described. Vinyl halides were prepared in good to excellent yields from enolizable ketones, whereas aldehydes afforded the corresponding gem-dihalides. The halogenation proceeded smoothly under mild conditions.
First catalytic and green synthesis of aryl-(Z)-vinyl chlorides and its plausible addition-elimination mechanism
Su, Weike,Jin, Can
, p. 993 - 996 (2007/10/03)
(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.
Convenient synthesis of aryl-substituted halo olefins from aromatic ketones and acetyl halides in the presence of silica gel-supported zinc halides
Kodomari, Mitsuo,Nagaoka, Takashi,Furusawa, Yuhsuke
, p. 3105 - 3107 (2007/10/03)
A simple and efficient procedure has been developed for the synthesis of aryl-substituted chloro and bromo olefins from aromatic ketones and acetyl halides in the presence of silica gel-supported zinc halides. The Z-isomer is selectively formed.
Direct preparation of vinyl halides from the corresponding ketones and acetyl halides
Moughamir, Khadija,Mezgueldi, Bouchra,Atmani, Aziz,Mestdagh, Helene,Rolando, Christian
, p. 59 - 62 (2007/10/03)
Vinyl chlorides and bromides are obtained in good yield from the corresponding ketones and acetyl halides in the presence of trifluoroacetic or trifluoromethanesulfonic acid. The Z isomer is selectively formed.
Surface-Mediated Reactions. 4. Hydrohalogenation of Alkynes
Kropp, Paul J.,Crawford, Scott D.
, p. 3102 - 3112 (2007/10/02)
The use of appropriately prepared silica gel and alumina has been found to mediate the addition of hydrogen halides to alkynes.The technique has been rendered even more convenient by the use of various organic and inorganic acid halides that react in the presence of silica gel or alumina to generate hydrogen halides in situ.Treatment in this fashion of 1-propynylbenzene (1), which underwent no reaction in CH2Cl2 solution saturated with HCl, readily afforded the syn addition product, alkenyl chloride (E)-4a.On extended treatment (E)-4a underwent subsequent iaomerization to the thermodynamically more stable Z isomer.Thus either isomer of 4a could be obtained in good yield depending on the reaction conditions.In a similar way bromides (E)- and (Z)-4b were obtained without competing formation of the radical products (E)- and (Z)-5, which occurred in solution.In contrast with solution-phase hydroiodination of alkyne 1, which slowly afforded iodide (E)-4c, surface-mediated addition readily afforded (E)-4c, followed by isomerization to the Z isomer.E ->/- Z equilibration of the alkenyl halides 4 was shown to involve, at last in part, addition-elimination via the gem-dihalides 13.Analogous behavior was exhibited by the phenylalkynes 2 and 3 on surface-mediated hydrohalogenation.Surface-mediated addition of HBr and HI to the internal alkylalkyne 14 afforded principally the anti addition products (Z)-15b,c.Treatment of the terminal alkynes 17 and 22 with (COBr)2 over alumina gave the dibromides 20 and 24/25, respectively, whereas use of acetyl bromide as the HBr precursor afforded the alkenyl bromides 18b and 23.
Phenylselenium Trichloride in Organic Synthesis. Reaction with Unsaturated Compounds. Preparation of Vinylic Chlorides via Selenoxide Elimination
Engman, Lars
, p. 4086 - 4094 (2007/10/02)
Phenylselenium trichloride, PhSeCl3, was reacted with a number olefinic compounds to produce (β-chloroalkyl)phenylselenium dichlorides.The addition was anti stereospecific and irreversible.The presence of an oxygen substituent (acyloxy or aryloxy group) in the allylic position of the olefin directed the attack of PhSeCl3 to occur regiospecifically anti-Markovnikov to give a (β-acyloxy/aryloxy-β'-chloroalkyl)phenylselenium dichloride.When the (β-chloroalkyl)phenylselenium dichlorides were treated in methylene chloride with aqueous sodium hydrogen carbonate, the selenium dichloride moiety was readily hydrolyzed to a selenoxide, which underwent the usual selenoxide elimination reaction to produce an allylic or a vinylic chloride.Symmetrical olefins containing no allylic hydrogens were converted to vinylic chlorides with retention of olefin geometry.Olefins containing a directing oxygen substituent in the allylic position afforded vinylic chlorides where the vinylic halogen atom was oriented 1,3 to the oxygen substituent (E/Z mixture).Other olefins afforded mixtures of allylic and vinylic halides in varying proportions.The reaction of phenyselenium tribromide, PhSeBr3, with some olefinic compounds was also investigated.This material showed the same stereo- and regiochemical behavior as PhSeCl3 in its addition reactions.However, the adducts were not useful for the preparation of vinylic or allylic bromides by using the hydrolytic selenoxide elimination reaction.
BROMOCHLORINATION OF ALKENES WITH DICHLOROBROMATE(1 minus ) ION. II. REGIO- AND STEREOCHEMISTRY FOR THE BROMOCHLORINATION OF 1-PHENYLPROPENES WITH DICHLOROBROMATE(1 minus ) ION.
Negoro,Ikeda
, p. 2116 - 2120 (2007/10/02)
The bromochlorinations of 1-phenylpropenes with tetrabutylammonium dichlorobromate(1 minus ) in aprotic solvents (dielectric constants 5-36) were found to be completely anti stereospecific and nonregiospecific, although Markownikoff adduct was mainly form
