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1.
Evans JW Fierman MB Miller SJ Ellman JA 《Journal of the American Chemical Society》2004,126(26):8134-8135
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. 相似文献
2.
Han Z Krishnamurthy D Grover P Fang QK Senanayake CH 《Journal of the American Chemical Society》2002,124(27):7880-7881
Simple and practical asymmetric synthesis of functionally differentiated aminoindanol based endo-N-sulfonyl 1,2,3-oxathiazolidine-2-oxide as sulfinyl transfer agents are developed. The importance of these new and unique sulfinyl transfer reagents are exemplified by the expedient production of several sulfinamide ligands, including either enantiomer of (R)-tert-butanesulfinamide in excellent yields and enantiopurities. 相似文献
3.
Synthesis of Polycyclic Tertiary Carbinamines by Samarium Diiodide Mediated Cyclizations of Indolyl Sulfinyl Imines
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Dr. Chintada Nageswara Rao Prof. Dr. Dieter Lentz Prof. Dr. Hans‐Ulrich Reissig 《Angewandte Chemie (International ed. in English)》2015,54(9):2750-2753
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. 相似文献
4.
[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. 相似文献
5.
Efficient one-pot transformation of 3-aza-1,5-enynes to poly-substituted pyridines in good to excellent yields has been developed. This reaction involved cyclization of 3-aza-enynes and elimination of sulfinyl acids steps. 相似文献
6.
Addition of alkyl or aryl Grignard reagents to N-sulfinyl imines derived from 3- and 4-substituted cyclohexanones proceeds with good yields and with excellent diasteroselectivity. The selectivity of the reaction is controlled by the ring substituent rather than the sulfinyl group stereochemistry, and therefore racemic tert-butanesulfinamide can be employed. 相似文献
7.
Han ZS Meyer AM Xu Y Zhang Y Busch R Shen S Grinberg N Lu BZ Krishnamurthy D Senanayake CH 《The Journal of organic chemistry》2011,76(13):5480-5484
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. 相似文献
8.
A zinc-mediated addition of methyl and terminal alkynes to chiral N-tert-butanesulfinyl ketimines for the preparation of optical quaternary 3-amino oxindoles was reported. In general, the operationally simple reaction affords the desired products in high yields and good to excellent diastereoselectivities. Subsequent convenient cleavage of sulfinyl protecting group under mild conditions was presented without racemization. 相似文献
9.
García Ruano JL Martín-Castro AM Tato F Pastor CJ 《The Journal of organic chemistry》2005,70(18):7346-7352
[reaction: see text] Optically pure functionalized cyanohydrins derived from 1-[2-(p-tolylsulfinyl)phenyl] ethanone can be obtained by the reaction of 2-p-tolylsulfinyl benzaldehyde derived cyanohydrins with bases and further treatment with suitable electrophiles. High yields and excellent stereoselectivities (up to de >98%) were obtained for these remote 1,4-asymmetric induction processes controlled by a sulfinyl chiral inductor. 相似文献
10.
Camille Pierry Philippe Jubault Thierry Lequeux Samuel Couve-Bonnaire 《Tetrahedron letters》2009,50(3):264-7404
Grignard and organolithium reagents efficiently react with (S)-N-(tert-butanesulfinyl)-α-fluoroenimines to provide chiral allylamines in excellent yields and with diastereomeric ratios of up to 96:4. Acidic removal of the sulfinyl group and simple functional group transformations allow to get enantiopure fluoroolefin dipeptide mimics. 相似文献
11.
Michał Rachwalski Stanisław Leśniak Ewelina Sznajder Piotr Kiełbasiński 《Tetrahedron: Asymmetry》2009,20(13):1547-1549
New tridentate enantiomerically pure heteroatom catalysts, containing hydroxyl, sulfinyl and amino groups, proved to be highly efficient in the enantioselective nitroaldol (Henry) reaction to give the desired adducts in very high yields (up to 90%) and with ees up to 98%. The influence of the stereogenic centres located on the sulfinyl sulfur atom and in the amine moiety is also discussed. 相似文献
12.
Alejandro Castellanos Iñaki Osante Jorge Fernández Roberto Fernández de la Pradilla Alma Viso 《Tetrahedron》2019,75(32):4287-4297
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. 相似文献
13.
Fernández de la Pradilla R Fernández J Manzano P Méndez P Priego J Tortosa M Viso A Martínez-Ripoll M Rodríguez A 《The Journal of organic chemistry》2002,67(23):8166-8177
The nucleophilic epoxidation of a variety of alpha'-(1-hydroxyalkyl) vinyl sulfones and sulfoxides has been studied. The sulfones give rise to anti oxiranes with modest (E) or excellent (Z) selectivities and in good yields. The (E)-sulfoxides display low reactivity within a reinforcing/nonreinforcing scenario. The use of t-BuOOLi in Et(2)O allows for a highly syn-selective epoxidation-oxidation. The (Z)-sulfoxides display a remarkably high reactivity under these conditions. The reinforcing (S,S(S)) diastereomers (3e-g) yield hydroxy sulfinyl oxiranes with high yields and selectivities. In contrast, the (R,S(S)) diastereomers (4e-g) show diminished reactivities and a very substrate-dependent stereochemical outcome. The structure of these oxiranes has been secured by chemical correlations and an X-ray crystal structure. 相似文献
14.
Fernández de la Pradilla R Tortosa M Lwoff N del Aguila MA Viso A 《The Journal of organic chemistry》2008,73(17):6716-6727
The highly selective base-promoted cyclization of enantiopure sulfinyl dienols affords allylic sulfinyl dihydropyrans. The scope of this methodology, including the preparation of seven-membered rings, has been studied in depth. The reactivity of our sulfinyl dihydropyrans toward oxidation, imination, and dihydroxylation has been explored, and thus several routes to densely functionalized pyran derivatives have been outlined. The reactivity of allylic dihydropyranyl sulfones and sulfoximines in S(N)2' processes with organocuprates has been examined. The displacement products were obtained with good regio- and stereoselectivity and fair to good yields. The reactivity of these products to dihydroxylation opens new possibilities to access enantiopure polyhydroxylated tetrahydropyrans that could be of interest for the synthesis of natural products. 相似文献
15.
Michał Rachwalski Stanisław Leśniak Piotr Kiełbasiński 《Tetrahedron: Asymmetry》2010,21(15):1890-1892
Enantiomerically pure tridentate heteroorganic catalysts, containing hydroxyl, sulfinyl, and aziridine moieties, have proven to be highly efficient in the enantioselective conjugate diethylzinc addition to chalcone and cyclohexenone to give the desired products in very high yields (up to 95%) and with ee’s up to 93%. The influence of the stereogenic centers located on the sulfinyl sulfur atom and in the aziridine moiety on the stereochemical course of the reaction is discussed. 相似文献
16.
Sulfines react with sulfinyl chlorides giving α-chloroalkyl alkanethiosulfonate esters and with thionyl chloride giving α-chloroalkanesulfenyl chlorides, both in good yields. 相似文献
17.
Fernández de la Pradilla R Manzano P Montero C Priego J Martínez-Ripoll M Martínez-Cruz LA 《The Journal of organic chemistry》2003,68(20):7755-7767
A novel route to enantiopure densely functionalized epoxy sulfinyl tetrahydrofurans, based on the unexpected and highly stereoselective remote nucleophilic epoxidation of hydroxy 1-sulfinyl butadienes with t-BuOOK, followed by ring closure and subsequent epoxidation of the resulting sulfinyl dihydrofurans, is described. Alternatively, the treatment of these dienes with m-CPBA followed by acid-catalyzed cyclization gives rise to related sulfonyl dihydrofurans in high yields but with low selectivity. The stereochemical outcome of the nucleophilic epoxidation of these substrates has also been studied. 相似文献
18.
Stanisław Leśniak Michał Rachwalski Ewelina Sznajder Piotr Kiełbasiński 《Tetrahedron: Asymmetry》2009,20(20):2311-2314
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. 相似文献
19.
[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. 相似文献
20.
A simple, environmentally friendly, and very efficient procedure for the synthesis of optically pure N-(tert-butylsulfinyl)imines has been developed with microwave-promoted condensation of aldehydes and ketones using (R)-2-methylpropane-2-sulfinamide in the presence of Ti(OEt)(4), under solvent-free conditions. This procedure allows for the preparation of a variety of sulfinyl aldimines with excellent yields and purities in only 10 min, making any further purification of the imines unnecessary. Several sulfinyl ketimines have also been prepared in good yields by extension of the reaction times to 1 h. This methodology has proved to be equally efficient for the synthesis of aromatic, heteroaromatic, and aliphatic N-(tert-butylsulfinyl)imines. Conventional heating has also been shown to be useful to promote these reactions, especially for the synthesis of aldimines. 相似文献