30439-34-0

Upstream product

• 593-60-2 Vinyl bromide 
• 168618-42-6 (2-methylsulfanylphenyl)boronic acid 
• 7022-45-9 2-(methylsulfanyl)benzaldehyde 
• 1779-49-3 Methyltriphenylphosphonium bromide 
• 30439-31-7 1-(2-Methylsulfanyl-phenyl)-ethanol 
• 446-52-6 2-Fluorobenzaldehyde 
• 2065-66-9 methyl-triphenylphosphonium iodide 
• 82135-95-3 1-methylthiaindan hexafluorophosphate 

Relevant academic research and scientific papers

Electrophile-promoted carbon - Sulfur bond cleavage in η2-thiophene complexes of pentaammineosmium(II)

Several S-alkylthiophenium complexes of the type [Os(NH3)5(4,5-η2-L)](OTf)3 (where L = S-alkylthiophenium, S-methylbenzo[b]thiophenium) are prepared by alkylation of the corresponding thiophene complexes. The S-

The Key Role of the Nonchelating Conformation of the Benzylidene Ligand on the Formation and Initiation of Hoveyda-Grubbs Metathesis Catalysts

Experimental studies of Hoveyda-Grubbs metathesis catalysts reveal important consequences of substitution at the 6-position of the chelating benzylidene ligand. The structural modification varies conformational preferences of the ligand that affects its exchange due to the interaction of the coordinating site with the ruthenium center. As a consequence, when typical S-chelated systems are formed as kinetic trans-Cl2 products, for 6-substituted benzylidenes the preference is altered toward direct formation of thermodynamic cis-Cl2 isomers. Activity data and reactions with tricyclohexylphosphine (PCy3) support also a similar scenario for O-chelated complexes, which display fast trans-Cl2?cis-Cl2 equilibrium observed by NMR EXSY studies. The presented conformational model reveals that catalysts, which cannot adopt the optimal nonchelating conformation of benzylidene ligand, initiate through a high-energy associative mechanism.

SULFUR CHELATED RUTHENIUM COMPOUNDS USEFUL AS OLEFIN METATHESIS CATALYSTS

Sulfur chelated ruthenium compounds represented by the following formula: wherein M indicates the ruthenium metal bound to a benzylidene carbon; R represents C1-C7 alkyl group or optionally substituted aryl; X1 and X2 each independently represent halogen; Y1 and Y2 each independently denote unsubstituted or alkyl-substituted phenyl; and Z independently represents hydrogen, electron withdrawing or electron donating substituent, with m being an integer from 1 to 4, and processes and compositions related thereto.

Studies on electronic effects in O-, N- and S-chelated ruthenium olefin-metathesis catalysts

A short overview on the structural design of the Hoveyda-Grubbs-type ruthenium initiators chelated through oxygen, nitrogen or sulfur atoms is presented. Our aim was to compare and contrast O-, N- and S-chelated ruthenium complexes to better understand the impact of electron-withdrawing and -donating substituents on the geometry and activity of the ruthenium complexes and to gain further insight into the trans-cis isomerisation process of the S-chelated complexes. To evaluate the different effects of chelating heteroatoms and to probe electronic effects on sulfur- and nitrogen-chelated latent catalysts, we synthesised a series of novel complexes. These catalysts were compared against two well-known oxygen-chelated initiators and a sulfoxide-chelated complex. The structures of the new complexes have been determined by single-crystal X-ray diffraction and analysed to search for correlations between the structural features and activity. The replacement of the oxygen-chelating atom by a sulfur or nitrogen atom resulted in catalysts that were inert at room temperature for typical ring-closing metathesis (RCM) and cross-metathesis reactions and showed catalytic activity only at higher temperatures. Furthermore, one nitrogen-chelated initiator demonstrated thermo-switchable behaviour in RCM reactions, similar to its sulfur-chelated counterparts.

Synthesis of sulfur-containing aryl and heteroaryl vinyls via Suzuki-Miyaura cross-coupling for the preparation of SERS-active polymers

The preparation of sulfur-containing aryl and heteroaryl vinyl co-monomers via Suzuki-Miyaura cross-coupling between the corresponding mercaptomethyl arylboronates and in situ-generated vinyl bromides is described. Surface-enhanced Raman scattering (SERS) studies of the target compounds on gold nanoparticles confirmed their potential as spectroscopic tags in the fabrication of SERS-encoded polymers for combinatorial screening and biomedical diagnostics.

Sulfur chelated ruthenium compounds useful as olefin metathesis catalysts

Sulfur chelated ruthenium compounds and methods and compositions involving the same. A method may relate to subjecting an olefin to a metathesis reaction in the presence of a sulfur chelated ruthenium compound. A composition may relate to an olefin starting material dissolved in an organic solvent together with a sulfur chelated ruthenium compound.

Latent sulfur chelated ruthenium catalysts: Steric acceleration effects on olefin metathesis

A series of sulfur chelated dormant ruthenium olefin metathesis catalysts is presented. The catalysts prepared were shown to possess the uncommon cis-dichloro arrangement and were mostly inactive at room temperature. By systematically modifying the size of the substituent groups at the chelating sulfur atom, catalyst activity at different temperatures was significantly affected; more bulky substituents fomented activity at lower temperatures. The catalysts were also shown to be stable in solution and retained their catalytic activity even after being exposed to air for two weeks.

Homogeneous reactions of thiophenes with transition metals: A modeling approach for elucidation of the hydrodesulfurization mechanism and an effective method for the synthesis of unusual organosulfur compounds

The fragment [(triphos)RhH], generated by thermolysis of (triphos)RhH3 (1) in refluxing THF, reacts with thiophene (T) or benzo[b]thiophene (BT) to yield (triphos)Rh(η3-SCH=CH-CH=CH2) (2) and (triphos)Rh-(η3-S(C6H4)CH=CH2) (3), respectively [triphos = MeC(CH2PPh2)3]. Compound 2 is selectively protonated at the terminal metal-bonded carbon atom (C2) by HBF4·OEt2 to give, after anion exchange, the η4-C,C,C,S-thiocrotonaldehyde complex anti-[(triphos)Rh{η4-SCHCHCH(CH3)}]BPh4 (4), which reacts with CO to yield [(triphos)Rh(CO)-{η2-S=CH-CH=CH(CH3)}]BPh4 (5) and thermally isomerizes to syn-[(triphos)Rh{η4-SCHCHCH(CH3)}]BPh4 (6) in solution. Complex 4 also reacts with MeI by selective delivery of Me+ to the sulfur atom to give, after anion exchange, [(triphos)Rh(η3-MeSCH=CH-CH=CH2)]BPh4 (7). On the other hand, Ph3C+ selectively attacks the C2 carbon atom to yield [(triphos)Rh{η4-SCHCHCH(CH2CPh3)}]PF 6 (8), whose structure has been determined by X-ray diffraction. Complex 8 crystallizes in orthorhombic space group P212121 (no. 19) with a = 10.834(6) A?, b = 15.012-(6) A?, c = 39.902(9) A?, Z = 4, and V = 6489.66 A?3. The cation [(triphos)Rh{η4-SCHCHCH(CH2CPh3)}] + presents a distorted square pyramidal structure with one P atom occupying the apical position, while the remaining two P atoms plus the C6-S and the C7-C8 bonds occupy the basal sites; the C8 atom bears the trityl substituent. The vinylthiophenolate complex 3 is also selectively protonated at C2 with HBF4·OEt2 to yield [(triphos)Rh{η4-S(C6H4)-CH(CH 3)}]BPh4 (9), which undergoes an intramolecular hydrogen shift from carbon to sulfur slowly at room temperature and rapidly in refluxing THF to produce [(triphos)Rh{η3-HS(C6H4)CH=CH 2}]BPh4 (10); complex (10) is deprotonated by t-BuOK to reform 3. As in the case of 2, MeI and Ph3CPF6 react with 3 by selective attack of S and C, yielding [(triphos)Rh{η3-MeS(C6H4)CH=CH 2}]BPh4 (11) and [(triphos)Rh{η4-S(C6H4)CH(CH 2CPh3)}]-PF6 (12), respectively. All the rhodium complexes obtained by addition of electrophiles to 2 or 3 upon treatment with CO quantitatively transform into [(triphos)Rh(CO)2]Y (Y = BPh4, PF6), liberating the thio ligands in solution. In this manner we have prepared the new organosulfur compounds 2-n-propenyl-4-methyl-4H-1,3-dithiine, 5,5,5-triphenyl-trans-2-pentenethial, 2-ethylidenecyclohexadienethione, and 2-(3,3,3-triphenylpropylidene)cyclohexadienethione and provided a convenient synthetic method for cis-1-(methylthio)butadiene, 2-vinylthiophenol, and o-(methylthio)styrene, which have been previously made by more complicated multistep syntheses. The chemistry herein described provides useful information on the fundamental aspects of hydrodesulfurization catalysis as well as a novel entry into the synthesis of organosulfur compounds.

One-Electron Chemical Reductions of Phenylalkylsulfonium Salts

Twenty-two arylalkylsulfonium salts have been reduced with potassium in graphite in tetrahydrofuran and the sulfide products identified.Two trialkylsulfonium salts did not reduce under these conditions.Comparison of the sulfides from a series of monophenylalkylsulfonium salts reveals a leaving-group propensity of benzyl > secondary > primary > methyl > phenyl in a ratio of 28:(6.0 +/- 0.3):1.0:(0.53 +/- 0.09): 0.05.The cleavage ratio is shown to be independent of the electron source and the homogeneity of heterogeneity of the reaction in two cases.Multiplicative transitivity of the above ratios is not observed, although the same qualitative order is found for other comparisons.These results are interpreted in terms of the initial formation of a ?-ligand radical anion sulfonium cation, which undergoes cleavage to a carbon radical and a sulfide.This appears to be the first evidence for this type of structure in a sulfur system.Leaving-group propensities different from the above order are observed in reductions of diphenylsulfonium and benzo-fused sulfonium salts, and rationales are offered.The intermediates in these reactions appear to be different from those involved in radical additions to, or displacements on, sulfur.