Asymmetric Synthesis of Isocarbacyclin Based on the Olefination-Isomerization-Coupling Process with Chiral Sulfoximines

Bund, J.; Gais, Hans‐Joachim; Schmitz, E.; Erdelmeier, Irène; Raabe, Gerhard

doi:10.1002/(sici)1099-0690(199807)1998:7<1319::aid-ejoc1319>3.0.co;2-l

Cited by 23 publications

(23 citation statements)

References 74 publications

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“…Although differently substituted homoallylic alcohols of types II or III can be obtained by several methods, no single method is available whereby both can be secured in enantio‐ and diastereopure form from a common substituted allylic carbanion through adjustment of the reaction conditions 10−12. Selective conversions of the vinylic sulfoximines II and allylic sulfoximines III to the enantio‐ and diastereopure building blocks IV − VIII can be envisaged considering (i) the facile lithiation of vinylic sulfoximines4,13−17 and allylic sulfoximines2,5,11,12,18−24 at C‐α, (ii) the ready nickel‐catalyzed cross‐coupling reaction of vinylic sulfoximines with organometallics,4,15,25,26 (iii) the excellent Michael acceptor properties of vinylic sulfoximines and their (dialkylamino)sulfoxonium salts,27−30 (iv) the facile reduction of sulfoximines,31 (v) the ready S N reaction of allylic sulfoximines with copper organyls,5−7 (vi) the facile elimination of β‐hydroxy (dialkylamino)sulfoxonium salts under formation of epoxides,32,33 and (vii) the ready substitution of allylic sulfoximines 34. Thus, if attainable, sulfoximines II and III would be expected to considerably expand the range of synthetic possibilities available through the use of either enantio‐ and diastereopure homoallylic alcohols of types II and III bearing an alkyloxy group,35−42 a Cl atom,43−45 a (dialkylamino)carbonyloxy group,10e,46−51 or a silyl group52−54 instead of the sulfonimidoyl group, or by utilizing aldol‐type compounds55,56 and vinylic epoxides as starting materials 57.…”

Section: Introductionmentioning

confidence: 99%

N-Methylsulfonimidoyl-Substituted (2-Alkenyl)titanium Complexes: Application to the Synthesis of β- and δ-Sulfonimidoyl-Substituted Chiral Homoallylic Alcohols, X-ray Crystal Structure Analysis, and Fluxional Behavior

et al. 2000

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Enantiopure acyclic (E)‐ and (Z)‐configured allylic sulfoximines have been synthesized from N,S‐dimethyl‐S‐phenylsulfoximine and aldehydes by the addition− elimination−isomerization route through the intermediate generation of the corresponding (E)‐configured vinylic sulfoximines. Isomerization of the vinylic sulfoximines with DBU preferentially afforded the corresponding (Z)‐configured allylic sulfoximines, which were subsequently isomerized by DBU to preferentially yield the (E)‐isomers. Titanation of lithiated (E)‐configured allylic sulfoximines with ClTi(OiPr)3 furnished the corresponding bis(2‐alkenyl)diisopropyloxytitanium(IV) complexes, which reacted with aldehydes in the presence of ClTi(OiPr)3 with high regio‐ and diastereoselectivities at the γ‐position to give the corresponding (Z)‐anti‐configured δ‐N‐methylsulfonimidoyl‐substituted homoallylic alcohols in good yields. In the absence of ClTi(OiPr)3 at low temperatures, only one allylic moiety of the bis(alkenyl)diisopropyloxytitanium complex is transferred to the aldehyde. In this way, a cyclic lithiated allylic sulfoximine has been converted with high regio‐ and diastereoselectivity to the corresponding homoallylic alcohols bearing a vinylic sulfonimidoyl group. Titanation of lithiated (E)‐ and (Z)‐configured allylic sulfoximines with ClTi(NEt2)3 afforded the corresponding mono(2‐alkenyl)tris(diethylamino)titanium(IV) complexes, which reacted with aldehydes with moderate to high regioselectivities and high diastereoselectivities preferentially at the α‐position to give the corresponding syn‐configured β‐N‐methylsulfonimidoyl‐substituted homoallylic alcohols along with the (Z)‐anti‐configured δ‐N‐methylsulfonimidoyl‐substituted homoallylic alcohols in good yields. In this way, the cyclic lithiated allylic sulfoximine was converted with high regio‐ and diastereoselectivity to the corresponding isomeric homoallylic alcohols bearing an allylic sulfonimidoyl group. In the case of mono(alkenyl)tris(diethylamino)titanium(IV) complexes, the regioselectivity of their reactions with aldehydes has been found to depend on the size of the substituent at the CC double bond and the aldehyde, as well as on the configuration of the double bond. Reaction of racemic lithiated N‐methyl‐S‐(3,3‐diphenyl‐2‐propenyl)‐S‐phenylsulfoximine with ClTi(OiPr)3 afforded the corresponding bis(alkenyl)diisopropyloxytitanium(IV) complex. X‐ray structure analysis revealed a distorted octahedral cis,cis,cis‐configured bis(2‐alkenyl)diisopropyloxytitanium(IV) complex, in which the allylic moieties are coordinated in a bidentate fashion through C‐α and the N atom to the Ti atom, both having the relative configuration RSSC. In solution, the titanium complex shows fluxional behavior, which is characterized by topomerization of the isopropyloxy groups and allylic moieties. The exchange of the latter occurs with retention of the configuration at C‐α.

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Section: Introductionmentioning

confidence: 99%

N-Methylsulfonimidoyl-Substituted (2-Alkenyl)titanium Complexes: Application to the Synthesis of β- and δ-Sulfonimidoyl-Substituted Chiral Homoallylic Alcohols, X-ray Crystal Structure Analysis, and Fluxional Behavior

et al. 2000

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“…We had previously realized the regioselective deconjugation of structurally analogous esters by using a chiral lithium amide 17. 21 Alcohol 8 was planned to serve at a late stage as a joint intermediate in the synthesis of 7 a and 7 b . The etherification and alkylation of the allyl alcohol 8 should give 15‐deoxy‐TICs 7 a and 7 b , respectively.…”

Section: Resultsmentioning

confidence: 99%

Magnetophoretic Continuous Purification of Single‐Walled Carbon Nanotubes from Catalytic Impurities in a Microfluidic Device

Kang

Park

2007

Small

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A magnetophoretic continuous purification method is presented of single-walled carbon nanotubes (SWCNTs) from the superparamagnetic iron-catalyst impurities in a microfluidic device without any influence on inherent SWCNT properties. By employing microfluidics and a magnetic-field-induced saw-tooth nickel microstructure, a highly enhanced magnetic force in adjoining microchannels is exploited. The iron impurities of SWCNTs are attracted towards areas of higher magnetic-flux density in the microchannels where magnetic field was asymmetrically generated perpendicularly to the streamline. We obtained highly purified SWCNTs at a rate of 0.36 mg h(-1) and that are estimated to be about 99% purity.

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“…47 However, despite an acceptable yield of 75%, the major diastereomer 41a could not be separated from the minor diastereomers 41b and 41c, and thus this method was not further considered for the synthesis of chiral bicyclo[3.3.0]octanones. On the other hand, the Pd-catalyzed cyclization required 34 mol% of Pd(OAc) 2 and 2.3 equivalents of Pb(OAc) 4 48 and gave 70% of the racemic diacetate 41b as a single diastereomer, which could be subjected directly to saponification and lipase-catalyzed optical resolution to give the monoacetate 41d, diacetate 41b, and diol 41e (Method B; Scheme 9). 49,50…”

Section: Scheme 7 4 Hydropentalenes Through Transannular Oxidative Cymentioning

confidence: 99%

Adventures and Detours in the Synthesis of Hydropentalenes

Deimling

Zens

Park

et al. 2020

Synlett

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Functionalized hydropentalenes (i.e., bicyclo[3.3.0]octanones) constitute important building blocks for natural products and for ligands for asymmetric catalysis. The assembly and tailored functionalization of this convex roof-shaped scaffold is challenging and has motivated a variety of synthetic approaches including our own contributions, which will be presented in this account.1 Introduction2 Biosynthesis of Hydropentalenes3 Hydropentalenes through the Pauson–Khand Reaction4 Hydropentalenes through Transannular Oxidative Cyclization of Cycloocta-1,4-diene5 Functionalization of Bicyclo[3.3.0]octan-1,4-dione to Dodecahydrocyclopenta[a]indenes6 Functionalization of Bicyclo[3.3.0]octan-1,4-diones to Crown Ether Hybrids7 Functionalization of Bicyclo[3.3.0]octan-1,4-dione to Cylindramide8 Tandem Ring-Opening Metathesis/Ring-Closing Metathesis/Cross-Metathesis of Bicyclo[2.2.1]heptanes9 Functionalization of Bicyclo[3.3.0]octan-1,4-dione to Geodin A10 Hydropentalenes through Enantioselective Desymmetrization of Weiss Diketones11 Functionalization of Weiss Diketones by Carbonyl Ene Reactions12 Functionalization of the Weiss Diketone to Cylindramide and Geodin A Core Units13 Biological Properties of Bicyclo[3.3.0]octanes14 Hydropentalenes through Vinylcyclopropane Cyclopentene Rearrangement15 Functionalization of Bicyclo[3.3.0]octanes toward Chiral Dienes16 Miscellaneous Syntheses of Hydropentalenes17 Conclusion and Outlook

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Asymmetric Synthesis of Isocarbacyclin Based on the Olefination-Isomerization-Coupling Process with Chiral Sulfoximines

Cited by 23 publications

References 74 publications

N-Methylsulfonimidoyl-Substituted (2-Alkenyl)titanium Complexes: Application to the Synthesis of β- and δ-Sulfonimidoyl-Substituted Chiral Homoallylic Alcohols, X-ray Crystal Structure Analysis, and Fluxional Behavior

N-Methylsulfonimidoyl-Substituted (2-Alkenyl)titanium Complexes: Application to the Synthesis of β- and δ-Sulfonimidoyl-Substituted Chiral Homoallylic Alcohols, X-ray Crystal Structure Analysis, and Fluxional Behavior

Magnetophoretic Continuous Purification of Single‐Walled Carbon Nanotubes from Catalytic Impurities in a Microfluidic Device

Adventures and Detours in the Synthesis of Hydropentalenes

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