- Phosphine/Sulfoxide-Supported Carbon(0) Complex
-
A new carbon(0) complex 2 with two different L ligands, a phosphine and a sulfoxide, was synthesized and fully characterized. This new type of carbone exhibits excellent coordination ability, in contrast to the related phosphine/sulfide-supported carbon(0
- Lozano González, Mariana,Bousquet, Laura,Hameury, Sophie,Alvarez Toledano, Cecilio,Saffon-Merceron, Nathalie,Branchadell, Vicen?,Maerten, Eddy,Baceiredo, Antoine
-
-
Read Online
- Reactivity in Methyl Transfer Reactions. 5. Relation between Rates and Equilibria
-
The methyl transfer reactions of two dimethylarylsulfonium ions with methyl phenyl sulfide are equilibrated in sulfolane solutions, as is the methyl transfer from methyldiphenylsulfonium ion to methyl 3,4-dichlorophenyl sulfide, and from dimethyl sulfate
- Lewis, Edward S.,Kukes, Semyon,Slater, Carl D.
-
-
Read Online
- Ni-Catalyzed Carboxylation of C(sp2)-S Bonds with CO2: Evidence for the Multifaceted Role of Zn
-
Nickel-catalyzed reductive carboxylation reactions of aryl electrophiles typically require the use of metallic reducing agents. At present, the prevailing perception is that these serve as both a source of electrons and as a source of Lewis acids that may aid CO2 insertion into the Ni-C bond. Herein, we provide evidence for the in situ formation of organometallic species from the metallic reductant, a step that has either been ruled out or has been unexplored in catalytic carboxylation reactions with metal powder reductants. Specifically, we demonstrate that Zn(0) acts as a reductant and that Zn(II) generates arylzinc species that might play a role in the C(sp2)-S carboxylation of arylsulfonium salts. Overall, the reductive Ni-catalyzed C(sp2)-S carboxylation reaction proceeds under mild conditions in a non-amide solvent, displays a wide substrate scope, and can be applied to the formal para C-H carboxylation of arenes.
- Yanagi, Tomoyuki,Somerville, Rosie J.,Nogi, Keisuke,Martin, Ruben,Yorimitsu, Hideki
-
p. 2117 - 2123
(2020/02/28)
-
- Sonogashira reaction using arylsulfonium salts as cross-coupling partners
-
Triarylsulfonium, alkyl- and fluoroalkyl(diaryl)-sulfonium, and aryl(dialkyl)sulfonium triflates are successfully used as a new family of cross-coupling participants in the Sonogashira reaction as aryldiazonium, diaryliodonium, and tetraphenylphosphonium salts. It was found that terminal alkynes reacted mildly with triarylsulfonium or (2,2,2-trifluoroethyl)diphenylsulfonium triflate at room temperature under Pdand Cu-cocatalysis to give the corresponding arylalkynes in up to >99% yield. This protocol represents the first use of arylsulfonium salts as cross-coupling partners in the Pd/Cu-catalyzed Sonogashira reaction.
- Tian, Ze-Yu,Wang, Shi-Meng,Jia, Su-Jiao,Song, Hai-Xia,Zhang, Cheng-Pan
-
supporting information
p. 5454 - 5457
(2017/11/06)
-
- Pd-catalyzed Suzuki–Miyaura cross-coupling of [Ph2SR][OTf] with arylboronic acids
-
The Pd-catalyzed Suzuki–Miyaura cross-coupling of alkyl- and fluoroalkyl(diphenyl)sulfonium triflates with arylboronic acids was compared. The fluorine substitution on the alkyl groups of [Ph2SR][OTf] had a big influence on the reaction. Perfluoroalkyl(diphenyl)sulfonium triflates (2b–d) were unsuccessful participants in the Pd-catalyzed phenylation of arylboronic acid under the standard conditions because of the strong electronegativity of the long-chain perfluoroalkyl groups, which underwent S[sbnd]Rfnbond cleavage instead. Polyfluoroalkyl(diphenyl)sulfonium triflates (2f–h) reacted with arylboronic acid to afford the phenylation product in very low yields due to the tendency of deprotonation and β-F elimination of the sulfonium salts. Eventually, (2,2,2-trifluoroethyl)diphenylsulfonium triflate (2e), methyl- or ethyl(diphenyl)sulfonium triflate (2i or 2j), and triphenylsulfonium triflate (2m) were found to be more effective reagents than other tested phenylsulfounium salts for Pd-catalyzed phenylation, which provided much higher yields of the desired products under mild conditions.
- Wang, Xiao-Yan,Song, Hai-Xia,Wang, Shi-Meng,Yang, Jing,Qin, Hua-Li,Jiang, Xin,Zhang, Cheng-Pan
-
p. 7606 - 7612
(2016/11/11)
-
- Synthesis and chemistry of enantiomerically pure 10,11-dihydrodibenzo[b,f] thiepines
-
Several chiral thiepines were efficiently constructed using sulfur diimidazole in combination with a variety of bislithiated carbon fragments. The sulfur atom in these thiepines is found to be unusually unreactive compared to diphenylsulfide. The Royal Society of Chemistry 2006.
- Wyatt, Paul,Hudson, Andrew,Charmant, Jonathan,Orpen, A. Guy,Phetmung, Hirihattaya
-
p. 2218 - 2232
(2008/02/04)
-
- Reactions of 5-(alkyl)thianthrenium and other sulfonium salts with nucleophiles
-
A series of 5-(alkyl)thianthrenium triflates (3a-d, g-i) with alkyl (R) groups Me (a), Et (b), isoPr (c), 2-Bu (d), cyclopentyl (g), cyclohexyl (h) and cycloheptyl (i) were prepared by alkylation of thianthrene (Th) with alkyl formate and trifluoromethanesulfonic (triflic) acid. Benzylation (3f) was achieved with benzyl bromide and silver triflate. 5-(Neopentyl)thianthrenium perchlorate (3e) was prepared by reaction of thianthrene cation radical perchlorate with dineopentyl mercury. Methyl- (4a) and cyclohexyldiphenylsulfonium triflate (4b) were made by alkylation of diphenyl sulfide. Benzyldimethyl- (5a), dibenzylmethyl- (5b) and benzylmethylphenylsulfonium perchlorate (5c) were prepared in standard ways. Reactions of these sulfonium salts with iodide ion and thiophenoxide ion were studied for comparison with our earlier reported reactions of comparable 5-(alkoxy)thianthrenium and methoxydiphenylsulfonium salts. It is deduced that reactions of 3-5 with nucleophiles (Nu-) I- and PhS- follow traditional SN2 and E2C paths. Thus, the salts 3a-c, e and f gave virtually quantitative yields of RNu and Th, while small amounts of butene(s) were obtained from 3d. The cycloalkyl salts 3g-i gave amounts of cycloalkylNu and cycloalkene typical of competition of SN2 and E2C routes in the classical reactions of cycloalkyl halides and tosylates with I- and PhS- ions. Whereas 4a gave only SN2 products, 4b gave SN2 and E2C products typical of SN2/E2C competition. Among the salts 5a-c displacement of the benzyl group was dominant (5a) or exclusive (5b, c), thus exhibiting the preferential displacement of a benzyl group that has been fully documented in earlier studies of SN2 reactions. Qualitative comparison showed that 3a (methyl) reacted much faster than 3e (neopentyl) with PhS-. Unlike alkoxysulfonium salts, the salts 3-5 do not appear to undergo reactions at the sulfonium sulfur atom. Copyright
- Liu, Bo,Shine, Henry J.
-
-
- Kinetic study of trifluoromethylation with S-(trifluoromethyl) dibenzothiophenium salts
-
The kinetic parameters were determined for C-trifluoromethylation of aniline with S-(trifluoromethyl)dibenzothiophenium triflate (1), its 3,7-dinitro derivative (2) and S-(trifluoromethyl)diphenylsulfonium triflate (3) in DMF-d7. The higher reactivity of heterocyclic 1 compared with non-heterocyclic 3 could be explained on the basis of its greatly enhanced activation entropy (ΔS≠: -11.2 cal mol-1 K-1 for 1; -47.1 for 3), but not its enhanced activation enthalpy (ΔH≠: 21.2 kcal mol-1 for 1; 12.1 for 3). The aromatic delocalization of the heterocyclic ring may thus be only slightly disturbed by the S-trifluoromethyl substituent. The high reactivity of 2 was attributed to the great electron deficiency caused by two nitro groups in addition to the heterocyclic salt system (ΔH≠ 17.0 kcal mol-1, ΔS≠ -9.1 cal mol-1 K-1 for 2). The reaction mechanism is discussed; the conventional SN2 attack mechanism was ruled out and a mechanism for a side-on attack to the CF3-S bond may possibly be applicable.
- Ono, Taizo,Umemoto, Teruo
-
p. 163 - 166
(2007/10/03)
-
- One-pot synthesis of aryl sulfoxides and sulfonium salts from sulfinic acid as a novel sulfurizing agent
-
Sodium sulfinate reacts electrophilically with aromatics in trifluoromethanesulfonic acid to give the corresponding aryl sulfoxides and sulfonium salts.
- Yamamoto, Kimihisa,Miyatake, Kenji,Nishimura, Yukio,Tsuchida, Eishun
-
p. 2099 - 2100
(2007/10/03)
-