Uncatalysed (thermal) and Lewis acid-promoted asymmetric hetero-Diels–Alder reaction of 1-thiabuta-1,3-dienes (thiochalcones) with di-(–)-menthyl fumarate. Configuration determination by X-ray crystallographic analysis of (2S,3R,4R)-(+)-2,3-bis[(–)-menthoxycarbonyl]-4,6-diphenyl-3,4-dihydro-2H-thiopyran and conversion of cycloadducts into optically pure diols

Saito, Takao; Fujii, H.; Hayashibe, S.; Matsushita, T.; Kato, Hideo; Kobayashi, Kimiko

doi:10.1039/p19960001897

Cited by 34 publications

(9 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The dimer would then be subjected to a retro-Diels-Alder reaction in the presence of diphenyldiazomethan (2a), which should lead to 2,3,5,5-tetraphenyl-2,3-dihydrothiophene (18) via 1,5-dipolar electrocyclization of the intermediate thiocarbonyl ylide with an extended π-system. Unfortunately, as reported by Li et al [15], we were unable to reproduce the results of Saito et al [14] and failed to isolate 15. The only product obtained after thionation of 17 was the so-called 'T-Dimer' 14 [15].…”

Section: Methodscontrasting

confidence: 47%

“…(14). It was attempted at first to synthesize the 'D-dimer' 15 of thiachalcone 16 by thionation of chalcone 17 [14]. The dimer would then be subjected to a retro-Diels-Alder reaction in the presence of diphenyldiazomethan (2a), which should lead to 2,3,5,5-tetraphenyl-2,3-dihydrothiophene (18) via 1,5-dipolar electrocyclization of the intermediate thiocarbonyl ylide with an extended π-system.…”

Section: Methodsmentioning

confidence: 99%

“…In order to make the thioketone less vulnerable to dimerization and to be able to carry out reactions with different diazo components, we extended the study to α,β-unsaturated thioketones with a β-amino substituent, i.e., to vinylogous thioamides. (14). It was attempted at first to synthesize the 'D-dimer' 15 of thiachalcone 16 by thionation of chalcone 17 [14].…”

Section: Methodsmentioning

confidence: 99%

“…Starting Materials. All thiocarbonyl derivatives and their precursors and all diazo compounds were prepared following known protocols: (phenyl)(3,4-dihydro-2,4,6-triphenyl-2H-thiopyran-3-yl)methanethione (14) [14], diphenyldiazomethane (2a) [8], phenyldiazomethane (2b) [21], diazomethane (2c) [22], diazocyclohexane (2d) [23], [24], (E)-1-phenyl-3-piperidinoprop-2-ene-1-thione (34) [20].…”

Section: Experimental Partmentioning

confidence: 99%

See 3 more Smart Citations

Reactions of Thioketones Possessing a Conjugated CC Bond with Diazo Compounds

Egli

Linden

Heimgartner

2006

Helvetica Chimica Acta

View full text Add to dashboard Cite

The reactions of several thioketones containing a conjugated C=C bond with diazo compounds were investigated. All of the selected compounds reacted via a 1,3-dipolar cycloaddition with the C=S group and subsequent N2 elimination to yield thiocarbonyl ylides as intermediates, which underwent a 1,3-dipolar electrocyclization to give the corresponding thiirane 25, or, by a subsequent desulfurization, to give the olefins 33a and 33b. None of the intermediate thiocarbonyl ylides reacted via 1,5-dipolar electrocyclization. If the a,b-unsaturated thiocarbonyl compound bears an amino group in the b-position, the reactions with diazo compounds led to the 2,5-dihydrothiophenes 40a-40d. In these cases, the proposed mechanism of the reactions led once more to the thiocarbonyl ylides 36 and thiiranes 38, respectively. The thiiranes reacted via an SNi'-like mechanism to give the corresponding thiolate/ammonium zwitterion 39, which underwent a ring closure to yield the 2,5-dihydrothiophenes 40. Also in these cases, no 1,5-dipolar electrocyclization could be observed. The structures of several key products were established by X-ray crystallography.

show abstract

Section: Methodscontrasting

confidence: 47%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Experimental Partmentioning

confidence: 99%

See 2 more Smart Citations

Reactions of Thioketones Possessing a Conjugated CC Bond with Diazo Compounds

Egli

Linden

Heimgartner

2006

Helvetica Chimica Acta

View full text Add to dashboard Cite

show abstract

“…[32][33][34][35] Therefore BF 3 etherate as well as ZnCl 2 were utilized as Lewis acids with a amount of 0.5 eq per functional unit thioamide. Addition of BF 3 resulted immediately in a brown precipitation and further degradation.…”

Section: Synthesis and Characterization Of 3b5 And The Oligomeric Spementioning

confidence: 99%

Reversible oligomerization of 3-aryl-2-cyanothioacrylamides via [2_s + 4_s] cycloaddition to substituted 3,4-dihydro-2H-thiopyrans

Kötteritzsch

Bode

Yildirim

et al. 2015

Designed Monomers and Polymers

View full text Add to dashboard Cite

(2015) Novel difunctional monomers are synthesized which are able to dimerize as well as oligomerize via the hetero-DielsAlder (HDA) mechanism. These monomers are based on 3-aryl-2-cyanothioacrylamides, which are used as functional units for the HDA reaction to form 3,4-dihydro-2H-thiopyrans. Different substituents of the aromatic ring are utilized to shift the equilibrium to the dimeric or oligomeric species. The HDA reaction is reversible and can be influenced by the temperature as well as the concentration. In contrast, the N,N-dimethylthioacrylamide analogues do not dimerize or the dimerization is not reversible. The most promising compound is furthermore investigated in detail by 1 H NMR spectroscopy to elucidate the dimerization kinetics. In addition, a difunctional molecule is able to oligomerize reversibly, as confirmed by means of 1 H NMR, size exclusion chromatography (SEC), and ESI MS measurements. A respective alcohol is employed as initiator for the ring-opening polymerization of L-lactide resulting in an end-functional polymer that undergoes reversible dimerization as confirmed by SEC measurements.

show abstract

Ruthenium Complexes of Thiocinnamaldehydes: Synthesis, Structure, and [4+2]‐Cycloaddition Reactions

Schenk

Beucke

Burzlaff

et al. 2006

Chemistry A European J

View full text Add to dashboard Cite

Ruthenium hydrogensulfido complexes [CpRu(P-P)(SH)] ((P-P)=Ph(2)PCH(2)PPh(2) (dppm), Ph(2)PC(2)H(4)PPh(2) (dppe)) were obtained from the corresponding chloro complexes by Cl/SH exchange. Condensation with a range of cinnamaldehydes gave thiocinnamaldehyde complexes [CpRu(P-P)(S=CH-CR(2)=CHR(1))]PF(6) (R(1)=C(6)H(4)X, R(2)=H, Me, X=H, OMe, NMe(2), Cl, NO(2)) as highly-colored crystalline compounds. The thiocinnamaldehyde complexes undergo [4+2]-cycloaddition reactions with vinyl ethers CH(2)=CHOR(3) (R(3)=Et, Bu) and styrenes H(2)C=CHC(6)H(4)Y (Y=H, Me, OMe, Cl, Br, NO(2)) to give complexes of 2,4,5-trisubstituted 3,4-dihydro-2H-thiopyrans as mixtures of two diastereoisomers. The rate of addition of para-substituted styrenes H(2)C=CHC(6)H(4)Y to [CpRu(dppm)(S=CH-CH=CHPh)]PF(6) increases in the series Y=NO(2), Br, Cl, H, Me, OMe, indicating that the cycloaddition is dominated by the HOMO(dienophile)-LUMO(diene) interaction. The strained dienophiles norbornadiene and norbornene also add, giving ruthenium complexes of 3-thia-tricyclo[6.2.1.0(2,7)]undeca-4,9-dienes and 3-thia-tricyclo[6.2.1.0(2,7)]undec-4-enes, respectively. Addition reactions with acrolein, methacrolein, methyl vinyl ketone, acrylic ester, or ethyl propiolate finally yielded ruthenium complexes of 3,4-disubstituted 3,4-dihydro-2H-thiopyrans and 4H-thiopyrans, respectively.

show abstract

Cited by 34 publications

References 42 publications

Reactions of Thioketones Possessing a Conjugated CC Bond with Diazo Compounds

Reactions of Thioketones Possessing a Conjugated CC Bond with Diazo Compounds

Reversible oligomerization of 3-aryl-2-cyanothioacrylamides via [2_s + 4_s] cycloaddition to substituted 3,4-dihydro-2H-thiopyrans

Ruthenium Complexes of Thiocinnamaldehydes: Synthesis, Structure, and [4+2]‐Cycloaddition Reactions

Contact Info

Product

Resources

About

Cited by 34 publications

References 42 publications

Reactions of Thioketones Possessing a Conjugated CC Bond with Diazo Compounds

Reactions of Thioketones Possessing a Conjugated CC Bond with Diazo Compounds

Reversible oligomerization of 3-aryl-2-cyanothioacrylamides via [2s + 4s] cycloaddition to substituted 3,4-dihydro-2H-thiopyrans

Ruthenium Complexes of Thiocinnamaldehydes: Synthesis, Structure, and [4+2]‐Cycloaddition Reactions

Contact Info

Product

Resources

About

Reversible oligomerization of 3-aryl-2-cyanothioacrylamides via [2_s + 4_s] cycloaddition to substituted 3,4-dihydro-2H-thiopyrans