32718-96-0Relevant academic research and scientific papers
The Electrochemical cis-Chlorination of Alkenes
Strehl, Julia,Fastie, Cornelius,Hilt, Gerhard
supporting information, p. 17341 - 17345 (2021/10/23)
The first example for the electrochemical cis-dichlorination of alkenes is presented. The reaction can be performed with little experimental effort by using phenylselenyl chloride as catalyst and tetrabutylammoniumchloride as supporting electrolyte, which also acts as nucleophilic reagent for the SN2-type replacement of selenium versus chloride. Cyclic voltammetric measurements and control experiments revealed a dual role of phenylselenyl chloride in the reaction. Based on these results a reaction mechanism was postulated, where the key step of the process is the activation of a phenylselenyl chloride-alkene adduct by electrochemically generated phenylselenyl trichloride. Like this, different aliphatic and aromatic cyclic and acyclic alkenes were converted to the dichlorinated products. Thereby, throughout high diastereoselectivities were achieved for the cis-chlorinated compounds of >95 : 5 or higher.
Catalytic, stereospecific syn-dichlorination of alkenes
Cresswell, Alexander J.,Eey, Stanley T.-C.,Denmark, Scott E.
, p. 146 - 152 (2015/03/04)
As some of the oldest organic chemical reactions known, the ionic additions of elemental halogens such as bromine and chlorine to alkenes are prototypical examples of stereospecific reactions, typically delivering vicinal dihalides resulting from anti-addition. Although the invention of enantioselective variants is an ongoing challenge, the ability to overturn the intrinsic anti-diastereospecificity of these transformations is also a largely unsolved problem. Here, we describe the first catalytic, syn-stereospecific dichlorination of alkenes, employing a group transfer catalyst based on a redox-active main group element (selenium). With diphenyl diselenide (PhSeSePh) (5amol%) as the pre-catalyst, benzyltriethylammonium chloride (BnEt 3 NCl) as the chloride source and an N-fluoropyridinium salt as the oxidant, a wide variety of functionalized cyclic and acyclic 1,2-disubstituted alkenes, including simple allylic alcohols, deliver syn-dichlorides with exquisite stereocontrol. This methodology is expected to find applications in streamlining the synthesis of polychlorinated natural products such as the chlorosulfolipids.
EPOXIDATION WITH THE H2O2/VILSMEIER REAGENT SYSTEM
Dulcere, Jean-Pierre,Rodriguez, Jean
, p. 1887 - 1888 (2007/10/02)
Alkenes 1 a-d interact at -80 deg C in 15 min. with the Vilsmeier reagent I (Me2N=CHCl)(+) PO2Cl2(-) in presence of 30percent H2O2 to yield the corresponding epoxides 3 a-d.The reaction could involve the formation of the highly reactive hydroperoxymethylenedimethylammonium salt (Me2N=CHOOH)(+) PO2Cl2(-) II.
