21213-27-4Relevant articles and documents
Sequential one-pot addition of excess aryl-grignard reagents and electrophiles to O-alkyl thioformates
Murai, Toshiaki,Morikawa, Kenta,Maruyama, Toshifumi
, p. 13112 - 13119 (2013/10/01)
The sequential addition of aromatic Grignard reagents to O-alkyl thioformates proceeded to completion within 30s to give aryl benzylic sulfanes in good yields. This reaction may begin with the nucleophilic attack of the Grignard reagent onto the carbon atom of the O-alkyl thioformates, followed by the elimination of ROMgBr to generate aromatic thioaldehydes, which then react with a second molecule of the Grignard reagent at the sulfur atom to form arylsulfanyl benzylic Grignard reagents. To confirm the generation of aromatic thioaldehydes, the reaction between O-alkyl thioformates and phenyl Grignard reagent was carried out in the presence of cyclopentadiene. As a result, hetero-Diels-Alder adducts of the thioaldehyde and the diene were formed. The treatment of a mixture of the thioformate and phenyl Grignard reagent with iodine gave 1,2-bis(phenylsulfanyl)-1,2-diphenyl ethane as a product, which indicated the formation of arylsulfanyl benzylic Grignard reagents in the reaction mixture. When electrophiles were added to the Grignard reagents that were generated insitu, four-component coupling products, that is, O-alkyl thioformates, two molecules of Grignard reagents, and electrophiles, were obtained in moderate-to-good yields. The use of silyl chloride or allylic bromides gave the adducts within 5min, whereas the reaction with benzylic halides required more than 30min. The addition to carbonyl compounds was complete within 1min and the use of lithium bromide as an additive enhanced the yields of the four-component coupling products. Finally, oxiranes and imines also participated in the coupling reaction. Into the melting pot: The addition of excess aryl Grignard reagents and electrophiles to O-alkyl thioformates gives aryl sulfanes through four-component coupling reactions (see scheme). These reactions may involve the formation of aromatic thioaldehydes and aryl-benzylic Grignard reagents as intermediates. For addition to carbonyl compounds, the use of lithium halides as an additive enhanced the efficiency of the reaction. Copyright
An efficient radical procedure for the halogenation and chalcogenation of B-alkylcatecholboranes
Schaffner, Arnaud-Pierre,Montermini, Florian,Pozzi, Davide,Darmency, Vincent,Scanlan, Eoin Martin,Renaud, Philippe
supporting information; experimental part, p. 1163 - 1167 (2009/06/05)
An efficient formal anti-Markovnikov addition of HX (X = Cl, Br, I, SR and SeR) to olefins under mild reaction conditionsisdes cribed. The procedure isbas ed on the hydroboration of alkeneswith catecholborane. The conversion of the intermediate B-alkylcatecholboranesto the corresponding halides, sulfides and selenides is based on a common process, i.e., generation of a radical from the alkylborane followed by abstraction of a heteroatom from an aromatic sulfonyl reagent. The efficiency of these radical reactionsis remarkable. The mildness of the reaction conditions is well illustrated by the preparation of iodoalkanes. Despite the notorious reactivity of iodoalkanes under radical reaction conditions, no product degradation wasobs erved.
α-(Benzotriazolyl)methyl phenyl thioethers: Convenient reagents for α-phenylthioalkylation of silylated nucleophiles
Katritzky, Alan R.,Chen, Jie,Belyakov, Sergei A.
, p. 6631 - 6634 (2007/10/03)
Stable, crystalline α-(benzotriazolyl)methyl phenyl thioethers (1), easily prepared from carbonyl compounds, thiophenol and benzotriazole, are convenient reagents for the phenylthiomethylation of trimethylsilyl cyanide, trimethylallylsilane, and trimethyl
