5533-32-4Relevant academic research and scientific papers
Cobalt-Catalyzed Redox-Neutral Sulfonylative Coupling from (Hetero)aryl Boronic Acids, Ammonium Salts and Potassium Metabisulfite
Fan, Qiangwen,Le, Zhang-Gao,Xie, Zongbo,Yang, Liu,Zhang, Yingying,Zhu, Haibo
, (2022/01/08)
An efficient cobalt-catalyzed redox-neutral sulfonylative coupling to afford (hetero)aryl alkyl sulfones from boronic acids, ammonium salts and potassium metabisulfite has been realized. Commercially available and air-stable CoCl2, in combination with phenanthroline ligand, is sufficient to achieve rapid and high-yielding conversion of the reactants into the corresponding sulfones. This practical transformation proceeds smoothly through C?N bond cleavage under redox-neutral catalytic conditions and shows broad functional-group tolerance. Other carbon based electrophiles, including diaryliodonium salts, heteroaryl halides, and carbonates were compatible. Further transformation of aryl alkyl sulfones then allows conversion into olefins, alkenyl sulfones and halogenated sulfones, respectively, in a one-pot process.
Unexpected differences in the α-halogenation and related reactivity of sulfones with perhaloalkanes in KOH-t-BuOH
Meyers, Cal Y.,Chan-Yu-King, Roch,Hua, Duy H.,Kolb, Vera M.,Matthews, Walter S.,Parady, Thomas E.,Horii, Toyokazu,Sandrock, Paul B.,Hou, Yuqing,Xie, Songwen
, p. 500 - 511 (2007/10/03)
Most alkyl phenyl sulfones are readily α-chlorinated with CCl4 and α-brominated with CBrCl3 in KOH-t-BuOH via radical-anion radical pair (RARP) reactions. While isopropyl mesityl sulfone (4) is easily α-chlorinated with CCl4, it was completely recovered when treated with the more reactive CBrCl3. Subsequent investigations showed the latter result to be due to the poor acidity of 4 together with the rapid depletion of CBrCl3 and KOH by their reaction with each other, and led to a variety of other important results. 4-Hydroxyphenyl isopropyl sulfone (6) is unreactive with either CCl4 or CBrCl3 in KOH-t-BuOH, its phenoxide anion strongly reducing the electronegativity of the sulfonyl group, thereby inhibiting α-anion formation. This effect is reversed by the electron-withdrawing influence of two α-phenyls, so that benzhydryl 4-hydroxyphenyl sulfone (8) is readily α-halogenated in KOH-t-BuOH with CCl4 or CBrCl3. On further contact with KOH-t-BuOH the α-halogenated sulfones from 8 are decomposed into benzophenone and phenol. While the α-halogenated derivatives of 4-methoxyphenyl benzhydryl sulfone (9) are stable to base, they are decomposed even under mildly acidic conditions into 4-methoxyphenyl 4-methoxybenzenethiolsulfonate (9c), phenol, and benzophenone. Mono-α-halogenation of benzyl phenyl sulfone (10) enhances the rate of the subsequent halogenation, so that α,α-dihalogenation is attained while much substrate is still present and the mono-α-halogenated product is not detected. The ease of reductive debromination of α-bromo sulfones with Cl3C- was correlated with the stability of the formed α-anions, explaining the success with α-bromobenzylic sulfones but failure with α-bromoalkyl sulfones. In the presence of air and the absence of competing halogenation, formation of the α-anions of alkyl aryl sulfones is quickly accompanied by oxidative cleavage by atmospheric O2, leading to the formation of arenesulfonyl alcohols, arenesulfonyl halides, and haloarenes.
Chlorinations with Carbon Tetrachloride under Conditions of Phase Transfer Catalysis
Lauritzen, Stein Erik,Roemming, Christian,Skatteboel, Lars
, p. 263 - 268 (2007/10/02)
Anion of ketones, sulfones and esters were α-chlorinated by carbon tetrachloride under conditions of phase transfer catalysis (PTC).Alcohols were unreactive.The observed products show that secondary reactions took place in many cases.The chlorination of the sulfone cis-2,5-diphenyltetrahydrothiophene-1,1-dioxide (1) occurred with inversion to give trans-2,5-dichloro-2,5-diphenyltetrahydrothiophene-1,1-dioxide (2).The structures of cis-1 and trans-2 were determined by X-ray diffraction.The reaction conditions are also applicable to brominations using bromotrichloromethane.
Process for producing aryl alpha-haloalkyl sulfones
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, (2008/06/13)
A process for preparing alkenes by reaction of various sulfone substrates with carbon tetrahalide in the presence of a strong base. The reactions are accelerated by the presence of a polar compound. Sulfone carbanions attack the carbon tetrahalide to produce an α-halogenated intermediate and a dihalocarbene. α-Halosulfones having α' hydrogens are converted to alkenes in situ via the Ramberg-Backland reaction. Sulfones having α but no α' hydrogens are simply α-halogenated. The dihalocarbene generated in the reaction may attack the product, solvent, or another substrate to form other products. Alkenes produced by reaction of carbon tetrahalides with di-sec-alkyl sulfones are readily attacked by dihalocarbene to form the alkene-dihalocarbene adduct (a substituted 1,1-dihalocyclopropane).
