Sulfinates tris

The family of poly(pyrazol-l-yl)borates has been widely used as supporting ligands in nickel coordination chemistry.556,557 Complex (191) is an example, where unusual cysteine coordination is achieved at a tris(pyrazolylborate)nickel(II) template.601 (191) undergoes rapid reaction with molecular oxygen to presumably form a sulfinate. 

Finally, it should be stressed that various nucleophilic and electrophilic reactions that lead from sulfoxides and sulfinates of known absolute configuration to new chiral tri- and tetracoordinate sulfur compounds and follow a stereochemically unambiguous course can be utilized for configurational assignments. Some of these reactions... 

Similar differentiation between enantiomers by means of NMR can also be achieved by the use of chiral lanthanide shift reagents (243). Tris-[3-(heptafluoropropylhydroxymethylene)-d-camphorato] -europium was used for the first time (244) for determining the enantiomeric content of benzyl methyl sulfoxide 34. The enantiomeric composition of the partially resolved methyl p-tolyl sulfoxide 41 was estimated using tris-[3-(r-butylhydroxymethylene)-c -camphorato]-europium (245). Another complex of europium, tris-[3-(trifluoro-methylhydroxymethylene)-c -camphorato] europium (TFMC), in contrast to those mentioned above, was effective in the differentiation of various enantiomeric mixtures of chiral sulfinates (107), thiosul-finates (35), and sulfinamides (246). 

Thus, the alkynyllithium derived from the propargylic ether 302 underwent allylzincation under the above-mentioned conditions and led to the dimetallic species 303. Whereas treatment with NBS resulted in the formation of the dibromoolefin 304, reaction of 303 with the less reactive benzenesulfonyl chloride produced an ce-chlorozinc sulfinate 305. The latter could in turn react with different electrophiles and afforded the corresponding tri- or tetra-substituted olefins of type 306 as single geometric isomers (equation 144)179. 

Trifluoromethylsulfate forms weak complexes with chromium(III) 821 this anion may provide a viable alternative to perchlorate as a non-coordinating anion (for Cr(03SCF3)3 see Section 35.7.2). Tris(0,0 -sulfinate) complexes of chromium(III) have been prepared (RSO2-, R = Me, C6H5, p-CH3C6H4) typical monomeric complexes are obtained.822... 

A novel synthesis of a-unsaturated sulfines has been introduced by Bra-verman et al. [99]. Et3N or DABCO treatment of allylic and benzylic tri-chloromethyl sulfoxides triggered the elimination of chloroform and formation of the sulfines. It must be stressed that these sulfines are thermally relatively stable, and this stands in high contrast to the corresponding thio-carbonyl compounds unsaturated thioaldehydes cannot be monitored under the same experimental conditions and have to be used at very low temperature or trapped in situ. The first synthesis of thioacrolein S-oxide was achieved by flash vacuum thermolysis of an anthracene allyl sulfoxide [100], and both isomers in a (Z E) ratio of 78 22 were characterised by NMR spectroscopy at -60 °C. 

You shouldn t at this stage try to leam ail the names for every type of organosulfur compound—what matters is the structures. Here the names are ail very similar and easily confused so. just for reference, here are the structures of a sulfonate ester (such as a tosylate or mesylate), a sulfinate ester, and a sulfenate ester. 

The chemistry of imidosulfinates is vastly unexplored [10] and nothing is known to date about the behavior of 0-allyl imidosulfinates in particular. By comparison with the known process C (Chart 1), the sulfinate-sulfone rearrangement (Sect. 2.2), it seems rather promising to try a new sulfoximine synthesis based on that rearrangement. 

Facing all the mechanism-related peculiarities of the thermally induced rearrangement it was consequential to try to shift the reaction toward one end of the mechanistic spectrum. The first steps in that direction were undertaken by Hiroi et ah in 1984 they reported on a palladium-catalyzed variant of the reaction [49]. With enantiomerically enriched sulfinates 61 (Scheme 16) they found a much faster reaction as compared to the uncatalyzed one, allowing a reduction of the reaction temperature down to - 78 °C ( ). The stereospecificity of the rearrangement depended heavily on the substitution pattern (between 28 and 92%) and was traced back to the intermediacy of a configurationally stable ri -jt-allylpalladium species whose configuration was influenced by the S centro chirality. Unfortunately, due to difficulties in the preparation of enantiomerically pure 2-alkenylsulfinates (see above), the ee values of the resulting allylic sulfones were quite low. 

A low-temperature study in superacid media of mono-, di-, and tri-protonated thiourea has been carried out. The experimental results were confirmed by theoretical calculations. Monoprotonation occiu s at sulfin and, whereas the mono- and di-protonated forms are thermodynamically stable, the triprotonated ion is only kinetically stable. The pyrolysis of A-acetylthiourea and iV,A -diacetylthiourea (335) are unimolecular first-order eliminations. Acid-catalysed ethanolysis of Nfl -dd- and tri-substituted aryl- and alkylaryl-thioureas gives O-ethyl 7V-aryl thiocarbamates and amines. The acid-catalysed hydrolysis of thiourea was first order in thiourea and acid. ... 

Via thermolysis of bismuth sulfinates (method L) Thermolysis of bismuth tris(arenesulfinate), which can be prepared from bismuth acetate and arenesulfinic acid in glacial acetic acid, leads to the formation of triarylbismuthines [72AJC2107]. 

The first synthesis of acetylenic sulfonate 72 was achieved by MCPBA oxidation of sulfinate 68 a to 71, followed by potassium fluoride desilylation, in 90% overall yield. However, to our surprise, the triisopropylsilyl-protected acetylenic sulfinate 68 b resisted oxidation with the oxidants we tried, including MCPBA, oxone, H202/Se02, and Ru04 generated from RuCl3/NaI04 [37],... 

In a similar way, pyridine phosphonium salts and phosphonates can be prepared by reaction of trivalent phosphorus compounds with the more accessible iV-trifluoromethanesulfonyl-pyridinium salts, when tri-fluoromethanesulfone is the leaving group from nitrogen (as sulfinate anion) attack is normally at C-4, as illustrated below. The A -trifluoromethanesulfonyl-pyridinium salts also react with ketones or with electron-rich aromatic compounds to give 1,4-dihydropyridine adducts. Subsequent treatment with potassium t-butoxide brings about elimination of trifluoromethanesulfinic acid, and thus aromatisation. It is also possible to utilise phosphonates in reaction with aldehydes, leading finally to 4-substimted pyridines. ... 

In desulfination of T1 sulfinates ", bis(polyfluorophenyl)thallium(III) bromide reacts with the corresponding Ba polyfluorobenzenesulfinate to give the tris(polyfluoro-phenyl)thallium(III) ... 

Sodium sulfinates NaRS02 (R = Me, Ph or MeCsILt) reacted in ethanol with VCI3 and tris(0,0 -sulfinato) complexes were obtained. The IR spectra are consistent with the sulfinato ions as bidentate. The electronic spectra show two d-d transitions Vi in the range... 

Deprotection of allyl carbonates has been accomplished using a wide variety of nucleophiles (Scheme 9), including formate, sodium borohydride, tri-n-butyl hydride, dimedone, diethylamine, and sodium azide. A recent, noteworthy development is the use of sulfinic acids as nucleophiles in the deprotection of allyl carbonates. Not only were allyl carbonates quantitatively deprotected in 30 min, but the authors also reported the successful deprotection of an allyl ether using catalytic palladium(O). Should this result prove to be general, it would represent in a major development in allyl-based protection of alcohols. 

Cg gHg gBNi02P3S, Bis(2-diphenylphosphinoethyl)phenyIphosphinenickel-(0-methyl sulfinate) tetraphenylborate, 46B, 1303 C60H40CI2F1202PnRh2 f Di(1,2-bis(diphenylphosphino)hexafluorocyclo-pentene)rhodiumd) cis-dicarbonyldichlororhodate(I), 37B, 668 CgoHs1CI2CU2P3 f Bis(triphenylphosphine)copper(I)-di-/x-chloro-tri-... 

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