59463-54-6Relevant academic research and scientific papers
Xanthates as Thiol Surrogates for Nucleophilic Substitution with Aryl Halides
Sokolov, Anatolii I.,Mikhaylov, Andrey A.,Baleeva, Nadezhda S.,Baranov, Mikhail S.
, p. 4350 - 4357 (2021/08/24)
We herein report an unprecedented xanthate-based protocol for the preparation of aryl-alkyl thioethers. Heating xanthates with aryl halides and namely cesium carbonate in methanol provides the target thioethers in generally good yields within short reaction times. This method allows one to avoid contact with odorous thiols and also to introduce substituents of which the corresponding thiols are virtually unavailable or inconvenient in use.
Methyl Radical Initiated Kharasch and Related Reactions
Tappin, Nicholas D. C.,Renaud, Philippe
supporting information, p. 275 - 282 (2020/12/07)
An improved procedure to run halogen atom and related chalcogen group transfer radical additions is reported. The procedure relies on the thermal decomposition of di-tert-butylhyponitrite (DTBHN), a safer alternative to the explosive diacetyl peroxide, to produce highly reactive methyl radicals that can initiate the chain process. This mode of initiation generates byproducts that are either gaseous (N2) or volatile (acetone and methyl halide) thereby facilitating greatly product purification by either flash column chromatography or distillation. In addition, remarkably simple and mild reaction conditions (refluxing EtOAc during 30 minutes under normal atmosphere) and a low excess of the radical precursor reagent (2 equivalents) make this protocol particularly attractive for preparative synthetic applications. This initiation procedure has been demonstrated with a broad scope since it works efficiently to add a range of electrophilic radicals generated from iodides, bromides, selenides and xanthates over a range of unactivated terminal alkenes. A diverse set of radical trap substrates exemplifies a broad functional group tolerance. Finally, di-tert-butyl peroxyoxalate (DTBPO) is also demonstrated as alternative source of tert-butoxyl radicals to initiate these reactions under identical conditions which gives gaseous by-products (CO2). (Figure presented.).
A Photochemical Organocatalytic Strategy for the α-Alkylation of Ketones by using Radicals
Goti, Giulio,Melchiorre, Paolo,O?eka, Maksim,Schweitzer-Chaput, Bertrand,Spinnato, Davide
supporting information, p. 9485 - 9490 (2020/04/09)
Reported herein is a visible-light-mediated radical approach to the α-alkylation of ketones. This method exploits the ability of a nucleophilic organocatalyst to generate radicals upon SN2-based activation of alkyl halides and blue light irradiation. The resulting open-shell intermediates are then intercepted by weakly nucleophilic silyl enol ethers, which would be unable to directly attack the alkyl halides through a traditional two-electron path. The mild reaction conditions allowed functionalization of the α position of ketones with functional groups that are not compatible with classical anionic strategies. In addition, the redox-neutral nature of this process makes it compatible with a cinchona-based primary amine catalyst, which was used to develop a rare example of enantioselective organocatalytic radical α-alkylation of ketones.
Efficient Synthesis of N-Benzyloxycarbonyl-2-aminoalkanesulfonyl Chlorides with Functionalized Side Chains
Abdellaoui, Hassane,Chen, Xingpeng,Xu, Jiaxi
, p. 2250 - 2256 (2017/05/05)
N-Benzyloxycarbonyl (Cbz)-protected 2-aminoalkanesulfonyl chlorides are useful building blocks for the synthesis of sulfonopeptides, which are receptor ligands and enzyme inhibitors, and are prepared by the coupling reaction of N-protected aminoalkanesulfonyl chlorides with amino acid or peptide esters. Various N-Cbz-protected 2-aminoalkanesulfonyl chlorides with functionalized side chains were synthesized through the radical addition of different xanthates to benzyl N-allylcarbamate and subsequent oxidative chlorination with tert-butyl hypochlorite under neutral conditions. A mechanism for the oxidative chlorination is proposed. This is a useful and convenient strategy for the synthesis of N-Cbz-protected 2-aminoalkanesulfonyl chlorides with diverse functionalized side-chains.
Expeditious synthesis of 1-substituted taurines with diverse functionalized side-chains
Kakaei, Saeed,Chen, Ning,Xu, Jiaxi
supporting information, p. 302 - 309 (2013/01/15)
A radical addition reaction and subsequent performic acid oxidation were used for the synthesis of 1-substituted taurines with diverse functionalized side-chains from N-allylphthalimide and various xanthates. The current approach shows high yields and short synthetic route and reaction time. Moreover, the current method is a convenient and practical method for the synthesis of 1-substituted taurines with different functionalized side-chains.
One-pot synthesis of symmetric 1,7-dicarbonyl compounds via a tandem radical addition-elimination-addition reaction
Huang, Zhongyan,Xu, Jiaxi
, p. 15114 - 15120 (2013/09/02)
A novel approach to synthesize symmetric 1,7-dicarbonyl compounds via a tandem radical addition-elimination-addition reaction of S-carbonylmethyl xanthates with allylmethylsulfone and its analogues has been developed. Radicals were produced from S-carbonylmethyl xanthates by adding dilauroyl peroxide and reacted with allylmethylsulfone or analogues to generate terminal olefins as intermediates. The excessive radicals reacted with the intermediate olefins immediately to give adducts of symmetric 1,7-dicarbonyl compounds. This is an efficient method to synthesize 1,7-dicarbonyl compounds under mild conditions. The Royal Society of Chemistry 2013.
Free-radical carboalkynylation and carboalkenylation of olefins
Liautard, Virginie,Robert, Frederic,Landais, Yannick
supporting information; experimental part, p. 2658 - 2661 (2011/06/26)
Free-radical three-component carboalkynylation and -alkenylation of olefins have been developed. These involve the addition, across the double bond of an unactivated olefin, of a radical species α- to an electron-withdrawing group and an alkenyl or alkynyl moiety, derived from the corresponding sulfones.
Synthetic approach to telomerase inhibitor dictyodendrin B: Synthesis of the pyrrolo[2,3-c]carbazole core
Hirao, Shotaro,Sugiyama, Yumiko,Iwao, Masatomo,Ishibashi, Fumito
experimental part, p. 1764 - 1772 (2010/03/24)
The core structure of the telomerase inhibitor, dictyodendrin B, was synthesized by using the palladium-catalyzed cross-coupling reaction of 3-aryl-1-(2-arylethyl)-4-hydroxy-2,5-bismethoxycarbonylpyrrole triflate with 7-alkoxyindole-3-boronate as the key step.
