New general sulfinylating process for asymmetric synthesis of enantiopure sulfinates and sulfoxides

[reaction: see text] A general process for the efficient synthesis of sulfinyl transfer agents has been developed using cinchona alkaloids quinine and quinidine as chiral auxiliaries. The importance of these new and unique sulfinyl transfer agents is exemplified by the expedient synthesis of several sulfoxides in excellent enantiopurities and high yields.     

Stereochemistry of transition metal catalyzed asymmetric intramolecular allyl transfer in chiral α-sulfinyl allylic esters

The stereochemistry of palladium or nickel catalyzed asymmetric intramolecular allyl transfer in chiral α-sulfinyl allylic esters was determined. The participation of the catalyst and the chiral sulfinyl functionality in these transformations, presumably by the coordination of the sulfinyl group to the catalyst, is discussed, and a novel mechanism is proposed for the rationalization of the results obtained.     

Catalytic enantioselective synthesis of sulfinate esters through the dynamic resolution of tert-butanesulfinyl chloride

Development of a new synthetic route to obtain enantiomerically enriched tert-butanesulfinate esters in excellent yields through catalytic enantioselective sulfinyl transfer is described. As little as 0.5 mol % of chiral amine catalysts was used to couple racemic tert-butanesulfinyl chloride with arylmethyl alcohols to provide sulfinate esters in near quantitative yields and with enantiomeric excesses up to 81%. The method represents the first example of the catalytic dynamic resolution of sulfinyl derivatives.     

Reaction of thiolsulfinates with trihaloacetic anhydrides—I : Evidence for the formation of sulfenyl and sulfinyl carboxylates

Thiolsulfinates react with trifluoro- or trichloroacetic anhydride to give equimolar mixtures of the corresponding disulfides and sulfinyl trifluoro- or trichloroacetates which are in equilibria with sulfenyl carboxylates. Although the equilibrium lies far toward sulfinyl carboxylates at room temperature, addition of olefins to the mixed solution of sulfinyl carboxylate and a corresponding disulfide affords the adducts which are formed in the reaction between the corresponding sulfenyl carboxylates and the olefins. Meanwhile, treatment of carboxylic acid silver salts with sulfinyl chlorides also gives sulfinyl carboxylates, however, sulfinyl carboxylates have not been successfully isolated yet.     

Enantioselective synthesis of diverse sulfinamides and sulfinylferrocenes from phenylglycine-derived chiral sulfinyl transfer agent

A new chiral sulfinyl transfer auxiliary derived from readily available phenylglycine was developed. This auxiliary is utilized to synthesize a diverse array of alkyl- and arylsulfinamides and sulfinylferrocenes in high yields and excellent ee's. The desired products are produced in a one-pot sequence from the oxathiazolidine 2-oxide by two sequential nucleophilic additions that proceed in a stereospecific manner.     

Catalytic enantioselective sulfinyl transfer using cinchona alkaloid catalysts

[reaction: see text] Practical reaction conditions for the catalytic enantioselective synthesis of sulfinate esters are reported. Commercially available cinchona alkaloids were found to be superior catalysts for the sulfinyl transfer reaction of tert-butanesulfinyl chloride and a variety of benzyl alcohols. Sulfinyl transfer with 2,4,6-trichlorobenzyl alcohol and 10 mol % of the commercially available, inexpensive catalyst quinidine provided the pure sulfinate ester product in 92% isolated yield and with 90% ee.     

三烃基（Ph,Cy,Bu）锡芳硫（亚砜,砜）乙酸酯的合成及表征

合成了２２种三烃基（Ｐｈ，Ｃｙ，Ｂｕ）锡芳硫（亚砜，砚）乙酸酯，用元素分析、ＩＲ、ＨＮＭＲ、ＭＳ、ＸＰＳ等手段对其结构进行了表征，结果表明，三环己基锡芳硫（亚砜、砜）乙酸酯具有四配位锡原子的单体结构，三苯基（三丁基）锡芳硫（亚砜、砜）乙酸醌具有五配位原子的聚合结构，通过估算它们的正辛醇－水分配系数，预测其在环境中的吸附及生物富集能力。     

正十六烷基磺酰氯的合成

正十六烷醇经亚磺酰甩作用转换成1－氯代正十六烷,在相转移催化剂条件下,1－氯代正十六烷和硫脲进行亲核反应,合成正十六烷基异硫脲盐酸盐,并以此为中间体用氯气氧化法制备正十六烷基磺酰氯,纯度大于95％,总收率为67％。     

Formal synthesis of ent-dysiherbaine from sulfinyl dihydropyrans by sigmatropic rearrangement and tethered aminohydroxylation

A stereospecific [2,3]-sigmatropic rearrangement of a sulfinyl dihydropyran, followed by a tethered aminohydroxylation reaction, are the key steps of a formal synthesis of ent-dysiherbaine from an enantiopure sulfinyl dienol.     

N-sulfinyl-substituted arylhydrazines from N-sulfinyltrifluoromethansulfonamide

Arylhydrazines react with N-sulfinyltrifluoromethanesulfonamide CF₃SO₂NSO providing N-sulfinylarylhydrazines and trifluoromethanesulfonamide. The discovered reaction is a first example of a transfer of a sulfinyl group from N-sulfinylsulfonamides to hydrazines. The reasons of different hydrolytic stability of CF₃SO₂NSO and ArNHNSO are discussed.     

Sulfoxide-directed enantioselective synthesis of functionalized dihydropyrans

[reaction: see text] The highly selective base-promoted cyclization of enantiopure sulfinyl dienols affords allylic sulfinyl dihydropyrans.     

Reversal of stereoselectivity in [5 + 2] pyrone--alkene cycloadditons using a sulfoxide-to-sulfoximine switch. Enantiodivergent synthesis of 8-oxabicyclo[3.2.1]octane systems

[reaction: see text] Switching from a sulfinyl to a sulfonimidoyl group allows the reversal of the sense of asymmetric induction in thermal [5C + 2C] intramolecular pyrone-alkene cycloadditions. Removal of the sulfoximine unit from the resulting cycloadducts yields optically active oxabicyclic systems that are enantiomeric to those obtained using the sulfinyl chiral auxiliary.     

Sulfenic acids in the carbohydrate field. Synthesis of transient glycosulfenic acids and their addition to unsaturated acceptors

A new method is described for building up anomeric glycosyl sulfoxides, via the formation of transient glycosulfenic acids and their addition to unsaturated acceptors. Thermolysis of alpha- and beta-3-[(2,3,4,6-tetra-O-acetyl-D-glucopyranosyl)sulfinyl]propanenitriles affords 1-glucosulfenic acids, which are reacted in situ with common substituted alkynes. The obtained (R(S),E)-2-[(2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl)sulfinyl]-2-butendioates are involved as enantiopure sulfinyl dienophiles in Diels-Alder reactions with 2,3-dimethyl-1,3-butadiene to evaluate the role that the sugar moiety plays in the steric control of the cycloaddition. This chemistry provides a direct synthetic strategy for the stereocontrolled connection between thioglycon and aglycon moieties, thus offering the basis for an easy elaboration of new molecules incorporating thiosugar residues.     

Studies on proton pump inhibitors. I. Synthesis of 8-[(2-benzimidazolyl)sulfinyl]-5,6,7,8-tetrahydroquinolines and related compounds

Many 8-[(2-benzimidazolyl)sulfinyl]-5,6,7,8-tetrahydroquinolines were synthesized and examined for their (H+ + K+) adenosine triphosphatase ATPase-inhibitory and antisecretory activities. These sulfinyl compounds could be considered to be rigid analogues of the 2-[(2-pyridyl)methylsulfinyl]benzimidazole class of antisecretory agents. All the compounds tested were potent inhibitors of (H+ + K+)ATPase. Most of the compounds also inhibited histamine-induced gastric acid secretion in rats. Among them, 8-[(5-fluoro-2-benzimidazolyl)sulfinyl]-3-methyl-5,6,7,8-tetrahydroqu inoline (XIVm) was found to have the most potent activity. The structure-activity relationships are discussed.     

Synthesis of Polycyclic Tertiary Carbinamines by Samarium Diiodide Mediated Cyclizations of Indolyl Sulfinyl Imines

Samarium diiodide mediated cyclizations of N‐acylated indole derivatives bearing sulfinyl imine moieties afforded polycyclic tertiary carbinamines with moderate to excellent diastereoselectivities. Lithium bromide and water turned out to be the best additives to achieve these transformations in good yields. Using enantiopure sulfinyl imines the outcome strongly depends on the reactivity of the indole moiety. Whereas with unactivated indole derivatives desulfinylation and formation of racemic products was observed, indoles bearing electron‐withdrawing substituents at C‐3 afforded the polycyclic products with intact N‐sulfinyl groups and with excellent diastereoselectivity, finally allowing the preparation of enantiopure tertiary carbinamines. The mechanisms of these processes are discussed.     

Oxidative reactions of sulfinyl dienes as an entry to functionalized carbohydrate-like products and furans

Oxidative cleavage (OsO₄/NaIO₄) of a monoprotected dihydroxy sulfinyl diene affords a lactol, readily transformed into a sulfinyl pyranose. Alternatively, base promoted intramolecular cyclization of a lactol derived carbamate to a bicyclic oxazolidinone followed by simple transformations leads to an amino sulfonyl pyranose. In contrast, ozonolysis of a variety of hydroxy sulfinyl dienes leads to fair yields of 3-sulfinyl furans in a single step.     

Sulfinyl-mediated stereoselective Overman rearrangements and Diels-Alder cycloadditions

The Overman rearrangement of allylic sulfinyl trichloroacetimidates affords sulfinyl trichloroacetamides with high stereoselectivity and excellent yields. Bis-allylic substrates lead to amido 2-sulfinyl butadiene derivatives in excellent yields, with total chemo- and diastereoselectivity. The Diels-Alder cycloaddition of related dienes is controlled by the sulfoxide moiety.     

New highly efficient aziridine-functionalized tridentate sulfinyl catalysts for enantioselective diethylzinc addition to carbonyl compounds

New tridentate enantiomerically pure heteroorganic catalysts, containing hydroxyl, sulfinyl, and aziridine moieties, have proven to be highly efficient in the enantioselective diethylzinc addition to aryl and alkyl aldehydes to give the desired products in very high yields (up to 99%) and with ee’s up to 97%. The influence of the stereogenic centers located on the sulfinyl sulfur atom and in the aziridine moiety on the stereochemical course of the reaction are discussed.     

Enantio- and diastereoselective addition of thioacetic acid to nitroalkenes via N-sulfinyl urea catalysis

The enantioselective addition of thioacetic acid to nitroalkenes was achieved using N-sulfinyl urea catalysis. In this report, the scope of the reaction was extended to the enantio- and diastereoselective thioacetic acid addition to cyclic α,β-disubstituted nitroalkenes. Additionally, the role of the sulfinyl group was investigated by replacing it with a variety of aryl and sulfonyl groups. Of 15 urea catalysts synthesized and tested, none displayed comparable selectivity to the sulfinyl catalysts, highlighting the importance of the sulfinyl group in attaining high enantioselectivity in the thioacetic acid addition.     

N-Phosphano nitrogen-containing five-membered aromatic chiral α-sulfoxides as new chiral ligands in asymmetric palladium-catalyzed allylic alkylation: stereoelectronic effects of the substituents on the aromatic rings

New chiral ligands, N-diphenylphosphano nitrogen-containing five-membered aromatic compounds bearing chiral sulfinyl groups as the sole chiral source has been developed. The structure of a palladium intermediate derived from the new chiral sulfoxide ligand was determined as a palladium complex with a five-membered chelate ring formed by coordination of the phosphano group and the sulfinyl sulfur atom involved. The stereoelectronic effects of substituents on the aromatic rings are discussed.