98815-48-6Relevant articles and documents
Alkene, Bromide, and ROH – How To Achieve Selectivity? Electrochemical Synthesis of Bromohydrins and Their Ethers
Bityukov, Oleg V.,Nikishin, Gennady I.,Terent'ev, Alexander O.,Vil', Vera A.
, p. 3070 - 3078 (2021)
Bromohydrins and their ethers were electrochemically synthesized via hydroxy- and alkoxybromination of alkenes using potassium bromide and water or alcohols. High selectivity of bromohydrins formation was achieved only with the use of DMSO as the solvent and an acid as the additive. The proposed combination of starting reagents, additives, and solvents allowed to form bromohydrins or their ethers selectively despite the variety of side-products (epoxides, dibromides, diols). Bromohydrins were obtained in high yields, up to 96%, with a broad substrate scope in an undivided electrochemical cell equipped with glassy carbon and platinum electrodes at high current density. (Figure presented.).
Reactions of 4-Substituted-2'-Halogenoacetophenones with Grignard Reagents
Crombie, Leslie,Hardy, Robert,Knight, David W.
, p. 1373 - 1380 (2007/10/02)
The initial reaction of 4-substituted 2'-halogenoacetophenones with an excess of methyl Grignard reagent is shown to be an attack at the 1'-carbonyl to form a halohydrin salt.The various reactions which then follow are substituent dependent.In the 4-hydroxy case the only product is 1-(4-hydroxyphenyl)-2-methylpropan-2-ol (13) which arises via a -aryl shift with simultaneous elimination of magnesium halide.When the substituent is 4-methoxy, a second pathway becomes important involving epoxide formation and a subsequent -hydride migration to the benzylic position, or attack of the Grignard reagent at the benzylic carbon of the epoxide.When the substituent is 4-bromo, the reaction proceeds exclusively via the epoxide and, following a -hydride shift, leads to the isomeric butanols (33) and (34).The reasons underlying such diversity of reactivity are discussed.
