Synthesis of aryl sulfides and diaryl sulfides

Name Reactions

Two Steps:

Leuckart Thiophenol Reaction

Recent Literature

A general palladium-catalyzed reaction using the CyPF-t-Bu ligand for the coupling of aryl halides and sulfonates with thiols exhibits extraordinary turnover numbers and high tolerance of functional groups.
M. A. Fernández-Rodríguez, Q. Shen, J. F. Hartwig, J. Am. Chem. Soc., 2006, 128, 2180-2181.

The well-defined palladium N-heterocyclic carbene (NHC) complex [Pd(IPr*^OMe)(cin)(Cl)] provides high catalytic activity for carbon-sulfur cross-coupling reactions of nonactivated and deactivated aryl halides with a large variety of aryl- and alkylthiols.
G. Bastug, S. P. Nolan, J. Org. Chem., 2013, 78, 9303-9308.

A copper-catalyzed coupling of aryl iodides with dimethyl disulfide in water enables an efficient route to aryl methyl sulfides in good yields. The reaction tolerates electron-donating and electron-withdrawing functional groups.
Y.-y. Wang, X.-m. Wu, M.-h. Yang, Synlett, 2020, 31, 1226-1230.

A mild, scalable, visible-light-promoted cross-coupling reaction between thiols and aryl halides provides various aryl thioethers in the absence of both transition metal and photoredox catalysts. This C-S coupling protocol was also applied in late-stage modifications of active pharmaceutical ingredients.
B. Liu, C. H. Lim, G. M. Miyake, J. Am. Chem. Soc., 2017, 139, 13616-13619.

An environment-friendly and economic CuCl₂-catalyzed C-S bond-formation enables the synthesis of diaryl chalcogenides in very good yields from iodobenzenes and benzenethiols/1,2-diphenyldisulfanes in the presence of N,N'-dimethylethane-1,2-diamine (DMEDA) as ligand, base, and solvent. The catalytic system (CuCl₂/DMEDA) is inexpensive, conveniently separable, and recyclable.
G. Shen, Q. Lu, Z. Wang, W. Sun, Y. Zhang, X. Huang, M. Sun, Z. Wang, Synthesis, 2022, 54, 184-198.

An operationally simple mechanochemical C-S coupling of aryl halides with thiols operates under benchtop conditions without the requirement for a (dry) solvent, an inert atmosphere, or catalyst preactivation. The reaction is finished within 3 h. The inclusion of zinc metal has been found to be critical for the coupling of alkyl thiols.
A. C. Jones, W. I. Nicholson, H. R. Smallman, D. L. Browne, Org. Lett., 2020, 22, 7433-7438.

A versatile and efficient Pd(OAc)₂/1,1'-bis(diisopropylphosphino)ferrocene-catalyzed cross-coupling of thiols with aryl halides was developed. Aryl bromides and chlorides can be coupled to aliphatic and aromatic thiols - the widest substrate scope of any reported to date. This catalyst system also enables the coupling of secondary phosphines with aryl halides.
M. Murata, S. L. Buchwald, Tetrahedron, 2004, 60, 7397-7403.

A convenient method for C-S cross-coupling of aryl bromides with various thiols involves the use of a 1,1′-bis(diphenylphosphino)ferrocene (DPPF)-ligated palladium complex with N,N-diisopropylethylamine (DIPEA) as the base. This coupling tolerates a wide range of functional groups, including hydroxy, amino, cyano, nitro, formyl, and carboxyl groups.
T. Okauchi, K. Kuramoto, M. Kitamura, Synlett, 2010, 2891-2894.

Highly chemoselective C-S cross-couplings of aryl, benzyl, and alkyl thiols with aryl and heteroaryl iodides were achieved versus competitive C-O and C-N cross-couplings in the presence of an Ir-photoredox catalyst. The reactions exhibit remarkable functional group tolerance and can be carried out in the presence of molecular oxygen.
M. S. Oderinde, M. Frenette, D. W. Robbins, B. Aquila, J. W. Johannes, J. Am. Chem. Soc., 2016, 138, 1760-1763.

Alkyl radicals generated from hypervalent alkylsilicates serve as effective hydrogen atom abstractors from thiols, furnishing thiyl radicals. A subsequent nickel-mediated cross-coupling with aromatic bromides provides thioethers. This thioetherification of various aryl and heteroaryl bromides with a diverse array of thiols tolerates a wide range of functional groups due to the S-H selective H atom abstraction event.
M. Jouffroy, C. B. Kelly, G. A. Molander, Org. Lett., 2016, 18, 876-879.

Air-stable defined Ni precatalysts enable a general and efficient coupling of challenging aryl chlorides and in situ generated aliphatic and aromatic thiolates at unprecedented moderate catalyst loadings and reaction temperatures. The reaction tolerates various functional groups and heterocyclic motifs. Depending on reaction conditions, aryl thiols can selectively undergo C-S or C-C couplings.
P. H. Gehrtz, V. Geiger, T. Schmidt, L. Sršan, I. Fleischer, Org. Lett., 2019, 21, 50-55.

The use of 2-pyridyl sulfides as sulfide donors enables a synthesis of aryl sulfides without using odorous and toxic thiols in the presence of a Ni/dcypt catalyst capable of cleaving and forming aryl-S bonds. This aryl exchange reaction works between 2-pyridyl sulfides and a broad range of aryl electrophiles, which include aromatic esters, arenol derivatives, and aryl halides.
R. Isshiki, M. B. Kurosawa, K. Muto, J. Yamaguchi, J. Am. Chem. Soc., 2021, 143, 10333-10340.

A metal-free, photocatalyst-free, photochemical system enables a direct alkylation of thiophenols via electron donor-acceptor complexes between N-hydroxyphthalimide esters as acceptors and thiophenol anions as donors in the presence of a tertiary amine. The EDA complexes in the reaction system have a broad range of visible-light absorption and can trigger the reaction effectively under sunlight.
Y.-P. Cai, F.-Y. Nie, Q.-H. Song, J. Org. Chem., 2021, 86, 12419-12426.

A cobalt-catalyzed coupling of aryl halides with thiophenols and alkanethiols allows the preparation of various aryl sulfides in excellent yields under mild reaction conditions.
Y.-C. Wong, T. T. Jayanth, C.-H. Cheng, Org. Lett., 2006, 8, 5613-5616.

Y.-C. Wong, T. T. Jayanth, C.-H. Cheng, Org. Lett., 2006, 8, 5613-5616.

An efficient CuSO₄-catalyzed S-arylation of thiols with aryl and heteroaryl boronic acids at room temperature is established. A wide variety of thiols and arylboronic acids can be converted in the presence of CuSO₄ as the catalyst, inexpensive 1,10-phen·H₂O as the ligand, oxygen as oxidant, and EtOH as environment-friendly solvent.
H.-J. Xu, Y.-Q. Zhao, T. Feng, Y.-S. Feng, J. Org. Chem., 2012, 77, 2649-2658.

A combination of copper(II) oxide and 1,10-phenanthroline catalyzes a microwave-promoted C-S bond formation of thiols and aryl iodides. Various aryl iodides react smoothly with thiols to provide the corresponding aryl sulfides in very good yields in water with a short reaction time. Amino, chloro, bromo, acetyl, and nitro groups are tolerated.
Y.-A. Chen. S. S. Badsara, W.-T. Tsai, C.-F. Lee, Synthesis, 2015, 47, 181-186.

A versatile photoinduced, copper-catalyzed method enables the coupling of aryl thiols with aryl halides at 0°C using inexpensive CuI as a precatalyst without the need for an added ligand. The reaction is effective for a wide range of coupling partners. Mechanistic investigations are consistent with photoinduced C-S cross-couplings following a SET/radical pathway for C-X bond cleavage (via a Cu(I)-thiolate).
C. Uyeda, Y. Tan, G. C. Fu, J. C. Peters, J. Am. Chem. Soc., 2013, 135, 9548-9552.

Diaryliodonium triflates transfer an aryl group to the chalcogen atom of organic sulfides, selenides, and tellurides. The reaction works in the absence of a transition-metal catalyst, simply upon heating in chloroform or dichloroethane solution.
L. Racicot, T. Kasahara, M. A. Ciufolini, Org. Lett., 2014, 16, 6382-6385.

Inodorous stable Na₂S₂O₃ is used as a sulfurating reagent in a Cu-catalyzed dual C-S bonds formation reaction, that proceeds in alcohol and water under air. This powerful strategy provides a practical and efficient approach to construct thioethers, using readily available aromatic amines and alkyl halides as starting materials. Sensitive and synthetic useful functional groups are tolerated.
Y. Li, J. Pu, X. Jiang, Org. Lett., 2014, 16, 2692-2695.

An acid-mediated coupling of thiols and thioethers with diaryliodonium salts enables the preparation of diaryl and alkyl aryl sulfides. The scope, limitations, and mechanism of the transformation are discussed.
A. M. Wagner, M. S. Sanford, J. Org. Chem., 2014, 79, 2263-2264.

Copper-catalyzed cross-coupling reactions of phenolic esters such as acetates, tosylates, and triflates with arylboronic acids or triphenyltin chlorides as the coupling partners in the presence of sulfur and a base provide unsymmetrical diaryl sulfides. In addition, NaOtBu promotes a synthesis of symmetrical diaryl sulfides from phenolic compounds in the presence of sulfur.
A. Rostami, A. Rostami, A. Ghaderi, M. Gholinejad, S. Gheisarzadeh, Synthesis, 2017, 49, 5025-5038.

The odorless and stable solid Na₂S₂O₃·5H₂O was used as a convenient and environmentally friendly source of sulfur in a Pd-catalyzed cross-coupling of aryl halides and alkyl halides to deliver aromatic sulfides.
Z. Qiao, J. Wei, X. Jiang, Org. Lett., 2014, 16, 1212-1215.

A Chan-Lam-type C-S coupling reaction using sodium aryl sulfinates provides diaryl thioethers in yields in the presence of a copper catalyst and potassium sulfite. Both electron-rich and electron-poor sodium aryl sulfinates and diverse organoboron compounds can be converted.
L. Y. Lam, C. Ma, Org. Lett., 2021, 23, 6164-6168.

A metal-free visible-light-promoted oxidative coupling between thiols and arylhydrazines provides diaryl sulfides in good yields using a catalytic amount of rose bengal as photocatalyst under aerobic conditions at room temperature. This methodology is also applicable to benzo[d]thiazole-2-thiols, benzo[d]oxazole-2-thiol, 1H-benzo[d]imidazole-2-thiols, and 1H-imidazole-2-thiol.
G. Kibriya, S. Mondal, A. Hajra, Org. Lett., 2018, 20, 7740-7743.

A mild, scalable iodine-mediated oxidative cross-coupling reaction of arylhydrazines and thiols enables the construction of thioethers (sulfides) in the absence of any transition metals or photocatalysts. A variety of unsymmetrical diaryl sulfides with broad substrate scope both on thiols and hydrazines were synthesized in high yields in water at room temperature.
F. Jafarpour, M. Asadpour, M. Azizzade, M. Ghasemi, S. Rajai-Daryasarei, Synthesis, 2020, 52, 727-734.

An efficient cross-coupling reaction of aryl/het-aryl/benzyl halides with stable and easily workable sulfonyl hydrazides as thiol substitutes delivers unsymmetrical sulfides in the presence [DBU][HOAc] and CuI under microwave irradiation.
N. Singh, R. Singh, D. S. Raghuvanshi, K. N. Singh, Org. Lett., 2013, 15, 5874-5877.

Pd- or Ni-catalyzed decarbonylative C-S coupling reactions transform thioesters into thioethers. The catalytic systems enable the construction of diaryl, aryl alkyl, and heterocycle-containing thioethers.
N. Ichiishi, C. A. Malapit, Ł. Woźniak, M. S. Sanford, Org. Lett., 2018, 20, 44-47.

[Rh(cod)Cl]₂ catalyzes a decarbonylative synthesis of valuable thioethers from thioesters in the absence of phosphine ligands, inorganic bases, and other additives. This thioetherification offers excellent group tolerance to aryl chlorides and bromides, gram scale synthesis, and late-stage pharmaceutical derivatization.
H. Cao, X. Liu, F. Bie, Y. Shi, Y. Han, P. Yan, M. Szostak, C. Liu, J. Org. Chem., 2021, 86, 10829-10837.

Cross-coupling of inexpensive ethyl potassium xanthogenate with aryl halides using recyclable CuO nanoparticles under ligand-free conditions followed by hydrolysis of the resulting xanthogenate ester and a subsequent cross coupling enables a synthesis of unsymmetrical sulfides in good to excellent yields. The copper oxide nanoparticles can be recovered and reused up to five cycles without loss of activity.
V. K. Akkilagunta, R. R. Kakulapati, J. Org. Chem., 2011, 76, 6819-6824.

In an efficient Cu-catalyzed one-pot approach for the synthesis of unsymmetrical diaryl thioethers through a Cu-catalyzed double arylation, the aryl thiols are generated in situ from an easily available xanthate and aryl halides. This strategy was further successfully utilized for the synthesis of symmetrical diaryl thioethers, aryl alkyl thioethers, and benzothiazoles.
D. J. C. Prasad, G. Sekar, Org. Lett., 2011, 13, 1008-1011.

An efficient coupling of arylboronic acids with dimethyldisulfide under metal-free conditions provides aryl methyl sulfides. The method offers operational simplicity, satisfactory yields, excellent functional-group tolerance, as well as mild reaction conditions.
X.-m. Wu, J.-m. Lou, G.-b. Yan, Synlett, 2016, 27, 2269-2273.

An Efficient Copper-Catalyzed One-Pot Synthesis of Diaryl Thioethers by Coupling of Arylboronic Acids with Potassium Ethyl Xanthogenate under Mild Conditions
L. Wang, W.-Y. Zhou, S.-C. Chen, M.-Y. He, Q. Chen, Synlett, 2011, 3041-3045.

Coupling of arylboronic acids with potassium ethyl xanthogenate enables a simple and environmentally benign one-pot synthesis of diaryl thioethers through a double arylation process. The aryl thiols were generated in situ, and the reactions proceeded smoothly to give the corresponding products in good to excellent yields under very mild conditions.
L. Wang, W.-Y. Zhou, S.-C. Chen, M.-Y. He, Q. Chen, Synlett, 2011, 3041-3045.

S-Alkyl, S-aryl, and S-vinyl thiosulfate sodium salts (Bunte salts), which can readily be prepared from sodium thiosulfate, react with Grignard reagents to give sulfides in good yields. The reaction is amenable to a broad structural array of Bunte salts and Grignard reagents. Importantly, this route to sulfides avoids the use of malodorous thiol starting materials or byproducts.
J. T. Reeves, K. Camara, Z. S. Han, Y. Xu, H. Lee, C. A. Busacca, C. H. Senanayaka, Org. Lett., 2014, 16, 1196-1199.

A single catalyst, derived from Pd(dba)₂ and NiXantPhos, efficiently catalyzes a debenzylative synthesis of diaryl sulfides from aryl benzyl sulfides and aryl bromides in good to excellent yields via α-arylation of sulfides, C-S bond cleavage, and C-S bond formation in a tricatalytic cycle.
J. Mao, T. Jia, G. Frensch, P. J. Walsh, Org. Lett., 2014, 16, 5304-5307.

cis-1,2-Cyclohexanediol is an efficient and versatile bidentate O-donor ligand that provides a highly active Cu-catalytic system for cross-coupling reactions of alkyl, aryl, or heterocyclic thiols with either alkyl, aryl, heterocyclic, or substituted vinyl halides. This new catalytic system promoted the mild and efficient stereo- and regiospecific synthesis of biologically important vinyl sulfides.
M. S. Kabir, M. Lorenz, M. L. V. Linn, O. A. Namjoshi, S. Ara, J. M. Cook, J. Org. Chem., 2010, 75, 3626-3643.

An efficient ligand-free Cu₂O-catalyzed C-S bond-formation reaction allows the assembling of a large number of diaryl sulfides and alkylaryl sulfides in good yields.
H.-J. Xu, X.-Y. Zhao, Y. Fu, Y.-S. Feng, Synlett, 2008, 3063-3067.

An aryl-sulfur bond formation between aryl iodides and thiophenols is catalyzed by a low amount of readily available and ligand-free copper iodide salt. Various diaryl thioethers are synthesized under relatively mild reaction conditions with good chemoselectivity and functional group tolerance.
E. Sperotto, G. P. M. van Klink, J. G. de Vries, G. van Koten, J. Org. Chem., 2008, 73, 5625-5628.

TAPC efficiently catalyzes the reaction of benzylic alcohols with aryl, heteroaryl, and alkyl thiols to afford thioethers in good to excellent yields. Furthermore, the reaction proceeds under metal-free and solvent-free conditions thus represents an interesting complement to known methods for thioether synthesis. A plausible mechanism is given.
K. Bahrami, M. M. Khodaei, N. Khodaboustan, Synlett, 2011, 2206-2210.

An efficient, indium triiodide-catalyzed substitution of the acetoxy group in alkyl, benzyl, allyl, and propargyl acetates with thiosilanes provides access to various thioethers.
Y. Nishimoto, A. Okita, M. Yasuda, A. Baba, Org. Lett., 2012, 14, 1846-1849.

Indium tri(organothiolate) derivatives are effective nucleophilic coupling partners in Pd-catalyzed C-S crosscoupling reactions to produce functionalized sulfides in excellent yields with high atom efficiency and complete regio- and chemoselectivity.
J.-Y. Lee, P. H. Lee, J. Org. Chem., 2008, 73, 7413-7416.

The use of copper(Ι) iodide as a catalyst, 4′-(4-methoxyphenyl)-2,2′:6′,2′′-terpyridine as ligand, and KOH as the base enables an efficient and convenient protocol for the copper-catalyzed reaction of aryl iodides with diorganyl disulfides and diselenides. Various symmetrical and unsymmetrical diaryl- and aryl alkyl chalcogenides were synthesized with good functional group tolerance and chemoselectivity.
B. Movassagh, Z. Hosseinzadeh, Synlett, 2016, 27, 777-781.

An eco-friendly coupling of diaryl disulfides and aryl iodides under ligand-free conditions with copper nanopowder as catalyst and PEG-400 as solvent enables the synthesis of varous unsymmetrical diaryl in very good yields. The process is odour-free and the copper nanopowder-PEG-400 catalytic system can be directly reused for four repetitive cycles.
X.-m. Wu, G.-b. Yan, Synlett, 2015, 26, 537-542.

Rongalite promotes a smoth, one-pot synthesis of aryl alkyl sulfides from disulfides and alkyl halides at room temperature. This protocol is metal-free, strong-base-free, and offers mild reaction conditions, operational simplicity, short reaction times and high yields of products.
R.-y. Tang, P. Zhong, Q.-l. Lin, Synthesis, 2007, 85-91.

Unsymmetrical diorgano-monosulfides, selenides, and tellurides can be synthesized by the coupling of dichalcogenides with aryl- or alkylboronic acids using a copper catalyst in air. The present reaction takes advantage of both organochalcogenide groups on the dichalcogenide.
N. Taniguchi, J. Org. Chem., 2007, 72, 1241-1245.

In three odorless methods for the thioarylation and thioalkylation of different nitroarenes using alkyl halides (Br, Cl), triphenyltin chloride, and arylboronic acids as the coupling partners, Na₂S₂O₃·5H₂O, S₈/KF, and S₈/NaOH systems are found to be effective sources of sulfur in the presence of copper salts. The methods offer use of green solvents, inexpensive catalysts, and user-friendly starting materials.
A. Rostami, A. Rostami, A. Ghaderi, J. Org. Chem., 2015, 80, 8694-8704.

In situ nitrosation of anilines followed by reduction with ascorbic acid to form aryl radicals and thiolation with disulfides provided aryl sulfides. This mild, metal-free synthesis of aryl sulfides proceeded smoothly without heating or irradiation. This strategy can be expanded to the synthesis of aryl selenides.
M.-j. Bu, G.-p. Lu, C. Cai, Synlett, 2015, 26, 1841-1846.

The reaction of diazonium tetrafluoroborates and diaryl dichalcogenides including sulfides, selenides and tellurides on the surface of alumina under ball-milling enables a convenient, efficient, and general synthesis of a wide range of diaryl chalcogenides in high purity without any solvent or metal.
N. Mukherjee, T. Chatterjee, B. C. Ranu, J. Org. Chem., 2013, 78, 11110-11114.

A highly efficient palladium-catalyzed cross-coupling of arenethiols and arylhydrazines with molecular oxygen as the sole oxidant provides unsymmetrical diaryl sulfides. The only byproducts are water and nitrogen. The reaction tolerates a broad range of functional groups, including reactive iodides.
C. Wang, Z. Zhang, Y. Tu, Y. Li, J. Wu, J. Zhao, J. Org. Chem., 2018, 83, 2389-2394.

1,1,1-Tris(hydroxymethyl)ethane as a New, Efficient, and Versatile Tripod Ligand for Copper-Catalyzed Cross-Coupling Reactions of Aryl Iodides with Amides, Thiols, and Phenols
Y.-J. Chen, H.-H. Chen, Org. Lett., 2006, 8, 5609-5612.

A mild, palladium-free method for C-S-bond formation is reported. The standard protocol gave aryl sulfides in excellent yields from thiols and iodides.
C. G. Bates, R. K. Gujadhur, D. Venkataraman, Org. Lett., 2002, 4, 2803-2806.

A nickel-catalyzed alkyl- or arylthiolation of aryl iodides with disulfides allows the preparation of various aryl sulfides. The in situ generated Ni(0)-bpy complex converts ArI into ArSR under neutral conditions. Furthermore, this system enables the use of only 0.5 eq. (RS)₂.
N. Taniguchi, J. Org. Chem., 2004, 69, 6904-6906.

A selective single arylsulfanylation of aryl diiodides with aryl or hetaryl thiols gives a broad array of iodine-functionalized aryl and hetaryl sulfides.
Y. Liu, H. Wang, X. Cao, Z. Fang, J.-P. Wan, Synthesis, 2013, 45, 2977-2982.

2,2-Diphenyl-1,3-oxathiolane slowly liberates a vinyl sulfide anion under basic conditions, that can be effectively used in Pd/Xantphos-catalyzed reactions with a wide range of aryl bromides to provide aryl vinyl sulfides.
J. R. Schmink, S. A. B. Dockrey, T. Zhang, N. Chebet, A. van Venrooy, M. Sexton, S. I. Lew, S. Chou, A. Okazaki, Org. Lett., 2016, 18, 6360-6363.

N-Alkynylthio phthalimides can be easily prepared in three steps from commercially available phthalimide and silver acetylides. N-Alkynylthio phthalimides are efficient electrophilic alkynylthiolating reagents that can react with various C-nucleophiles, including β-ketoesters, aryl boronic acids, and Grignard reagents to afford a diverse range of alkynyl thioethers under mild conditions.
W.-C. Gao, Y.-Z. Shang, H.-H. Chang, X. Li, W.-L. Wei, X.-Z. Yu, R. Zhou, Org. Lett., 2019, 21, 6021-6024.

A gold-catalyzed hydrothiolation of unactivated alkenes proceeds effectively to give anti-Markovnikov-selective adducts in good yields and in a regioselective manner.
T. Tamai, K. Fujiwara, S. Higashimae, A. Nomoto, A. Ogawa, Org. Lett., 2016, 18, 2114-2117.

The anti-Markovnikov addition of thiols to alkenes using CeCl₃ as catalyst leads to products in very good yields. The reaction occurred under solvent-free conditions at room temperature.
C. C. Silveira, S. R. Mendes, F. M. Líbero, Synlett, 2010, 790-792.

A highly selective anti-Markovnikov addition of thiols to unactivated alkenes in water at room temperature without any additive is a very simple and efficient method for the synthesis of linear thioethers.
B. C. Ranu, T. Mandal, Synlett, 2007, 925-928.

A visible light-promoted and tertiary-amine-assisted hydroxysulfenylation of both electron-rich and electron-deficient alkenes with thiophenols provides β-hydroxysulfides in very good yields. This simple and sustainable approach features mild reaction conditions, high efficiency, and excellent functional group tolerance.
J. Shi, X.-W. Gao, Q.-X. Tong, J.-J. Zhong, J. Org. Chem., 2021, 86, 12922-12931.

Insertion of sulfoxonium ylides into the S-H bond of aryl thiols provides β-keto thioethers in excellent yield without the need for a catalyst. The method avoids the use of metal catalysts in combination with diazo compounds or toxic haloketones.
R. M. P. Dias, A. C. B. Burtoloso, Org. Lett., 2016, 18, 3034-3037.

A cinchona alkaloid-derived urea is an efficient organocatalyst for catalyzing enantioselective conjugate addition between thiols and various α,β-unsaturated ketones to provide optically active sulfides with high chemical yields and enantiomeric excess. The reaction was performed with 0.1 mol % of catalyst in toluene at room temperature.
N. K. Rana, S. Selvakumar, V. K. Singh, J. Org. Chem., 2010, 75, 2089-2091.

A rapid conjugate addition of thiols to α,β-unsaturated ketones is achieved in a hydrophobic ionic liquid [bmim]PF₆/H₂O solvent system in the absence of any acid catalyst. This mild and neutral method gave the corresponding Michael adducts in high yields with excellent 1,4-selectivity. The ionic liquid can be reused.
J. S. Yadav, B. V. S. Reddy, G. Baishya, J. Org. Chem., 2003, 68, 7098-7100.

CeCl₃ • 7H₂O/NaI supported on neutral alumina (Al₂O₃) promotes heteroatom Michael additions under solvent-free conditions. The CeCl₃ • 7H₂O/NaI/Al₂O₃ system works well for hetero-Michael additions of weak nucleophiles such as imidazoles and carbamates to various acceptors.
G. Bartoli, M. Bartolacci, A. Giuliani, E. Marcantoni, M. Massaccesi, E. Torregiani, J. Org. Chem., 2005, 70, 169-174.

An efficient copper-catalyzed carbenoid insertion reaction of α-diazo carbonyl compounds into Si-H and S-H bonds provides a broad range of α-silylesters and α-thioesters in high yields using 5 mol% of a simple copper(I) salt as catalyst. In addition, α-diazoketones can be converted to α-silylketones in moderate yields.
H. Keipour, A. Jalba, L. Delage-Laurin, T. Ollevier, J. Org. Chem., 2017, 82, 3000-3010.

A mild, versatile, palladium-free method for the synthesis of vinyl sulfides using the soluble copper(I) catalyst [Cu(phen)(PPh₃)₂]NO₃ is reported. The desired vinyl sulfides are obtained with retention of stereochemistry in good to excellent yields.
C. G. Bates, P. Saejueng, M. Q. Doherty, D. Venkataraman, Org. Lett., 2004, 6, 5005-5008.

An efficient, mild and transition-metal-free N-arylation of amines, sulfonamides, and carbamates and O-arylation of phenols and carboxylic acids has been achieved by using various o-silylaryl triflates in the presence of CsF.
Z. Liu, R. C. Larock, J. Org. Chem., 2006, 71, 3198-3209.

A new synthetic method for the preparation of potassium organotrifluoroborates through nucleophilic substitution of potassium bromo- and iodomethyltrifluoroborates is described. Potassium halomethyltrifluoroborates have been prepared via in situ reaction of n-BuLi with dibromo- and diiodomethane, respectively, in the presence of trialkyl borates, followed by treatment with KHF₂.
G. A. Molander, J. Ham, Org. Lett., 2006, 8, 2031-2034.

A regio and anti-selective copper-catalyzed 1,2-hydroxysulfenylation of alkenes can be carried out by the use of disulfides and acetic acid. Reoxidation of intermediate sulfides by oxygen enables the use of both organosulfide groups of the disulfides.
N. Taniguchi, J. Org. Chem., 2006, 71, 7874-7876.

In a highly enantioselective method for desymmetrization of meso-epoxides with aromatic thiols, epoxide activation is achieved using metal BINOL phosphates. β-Hydroxyl sulfides are obtained in excellent yield and enantioselectivity for a broad scope of substrates.
G. Ingle, M. G. Mormino, J. C. Antilla, Org. Lett., 2014, 16, 5548-5551.