Thiiranium‐Ionen als Reaktionszwischenstufen

Mueller, W. H.

doi:10.1002/ange.19690811302

Cited by 61 publications

(7 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This is in line with the known stability of ethylene sulfonium ions in solution. 21 The yields of sulfonium and bromonium ions relative to their oxonium and chloronium analogues, respectively, correlates well with the difference in nucleophilicity of the relevant functionalities. This is also so when ammonium and dimethylammonium species are compared and holds equally for the methoxy (1,) and methylthio (3,) compounds relative to their phenoxy (2,) and phenylthio (4,) analogues (bearing in mind that for compounds 2, the identical terminal functionalities necessitate a statistical correction when comparing with l,,).…”

Section: Figs 1 3 and 4)mentioning

confidence: 90%

Cyclization reactions in the chemical ionization spectra of bifunctional alkyl phenyl ethers

Sande

Gaever

D'haenens

et al. 1979

Org. Mass Spectrom.

View full text Add to dashboard Cite

show abstract

Section: Figs 1 3 and 4)mentioning

confidence: 90%

Cyclization reactions in the chemical ionization spectra of bifunctional alkyl phenyl ethers

Sande

Gaever

D'haenens

et al. 1979

Org. Mass Spectrom.

View full text Add to dashboard Cite

show abstract

“…Die Regioselektivitat der Sulfenyl-chlorid-Additionen lasst sich rnit der Bildung eines intermediaren Thiiranium-Ions [24][25][26][27][28] vereinbaren, wobei diejenige (C-S)-Bindung gebrochen wird, die zum stabileren Carbokation fuhrt. Im Vorlaufer von 33 wird das sekundare Carbokation durch die (Trimethylsily1)oxy-Gruppe destabilisiert, so dass der Angriff von C1-selektiv an der CH,-Gruppe erfolgt.…”

Section: ' )unclassified

“…von 7 [47] 56,26,19,24,66 113,05,25.62,24,78 113,48,25,21,24,67 113,51,25,27,24,79 113,6O,25,43,24,91 113,71,25,40,24,91 p 5,00,25,59,26,99 109,30,25,70,26,94 109,31,25,81,26,96 109,40,25,93,27,OX 109,49,25,…”

Section: ' )mentioning

confidence: 99%

“…€l-C(S)); 3,90 (ddd, J = 3,0, 6,0, 12,0, H-C (6)); 3,78 (ddd, J = 5,0, 6,0, 12,0, H'pC (6) 3,63 (dd, J = 4,0, 8,0, 0,4 H, H-C(4)); 3,21 -3,34 (in, CHS); 2,58-2,69 (m, 0,4 H); 2,48 (m,0,6 H,OH);1,52,1,45,1,39,1,35 (4.7,4 Me). "C-NMR (CDC1,): 113,48, 109,30, X7,01 (33b), 85,73 (33a), 82,32 (33a), 82,14 (33b), 81,72, 80,10 (33b), 80,03 (33a), 72,90, 66,73, 63,36 (33b), 62,49 (33a), 50.77 (33b), 49,58 (33a), 44,44 (33a), 44,25 (33b), 26,94,25,70,25,21,24,67. EI-MS: 353 (9, [M -Me]+), 317 (2), 263 (6), 185 (46), 141 (13), 127 (17), 101 (73), 85 (23), 81 (15), 69 (13), 59 (40).…”

Section: 3:56-di-o-isopropyliden-mentioning

confidence: 99%

“…CDCI,): 4,86 (m,, H-C(2)); 4,78 (dd, J = 3 3 , 5,8, H-C(3)); 4,44 (ddd, J = 4,4, 6,1, 7,3, (m, 1 H); 3,63-3,88 (m, I H); 3,61 (dd, J = 3 3 , 7,3, H-C(4)); 3,14 (dt,4,1,6 3 ,CHS); 2,87 (dd, J = 4.7, 8 3 , OH); 1,63 (4 J = 6,6, Me); 1,53,1,44,1,37,1,36 (4s,4 Me). I3C-NMR (CDCI,): 113, 51,109,31,87,78,82,12,81,75,80,20,72,95,66,75,64,03,58,01,57,92,26,96,25,81,25,27,24,79,22, [M -Me]+), 316 (4), 243 (4), 227 (2), 185 (39), 141 (ll), 127…”

Section: 3:56-di-o-isopropyliden-mentioning

confidence: 99%

See 2 more Smart Citations

Glycosylsulfenyl‐ und (Glycosylthio)sulfenyl‐halogenide (Halogeno‐ bzw. Halogenothio‐(1‐thioglycoside)): Herstellung und Umsetzung mit Alkenen

Hürzeler

Bernet

Vasella

1992

Helvetica Chimica Acta

View full text Add to dashboard Cite

Glycosylsulfenyl and (Glycosylthio)sulfenyl Halides (Halogeno and Halogenothio 1-Thioglycosides, Resp.): Preparation and Reaction with AlkenesThe disulfides 11-17 and 20 were prepared from 7, 9, and 18 via the dithiocarbonates 8, 10, and 19, respectively (Scheme 2 ) . The structure of 11 and of 13 was established by X-ray analysis. Chlorolysis (SO,Cl,) of 1 1 gave mostly the sulfenyl chloride 24, characterized as the sulfenamide 26, a small amount of 21, characterized as the (g1ycosylthio)sulfenamide 23, and the glycosyl chloride 27 (Scheme 3). Bromolysis of 11 followed by treatment of the crude with PhNH, yielded only 28. Chlorolysis of the diglycosyl disulfide 13, however, gave mostly the (g1ycosylthio)sulfenyl chloride 21 and 27, besides 24. Bromolysis of 13 (-22 and traces of 25) followed by treatment with PhNH, gave an even higher proportion of 23. Similarly, 20 led to 29 and hence to 30. In solution (CHfJ,), the sulfenyl chloride 24 decomposes faster than the (thio)sulfenyl chloride 21, and both interconvert. Addition of crude 24 to styrene (-78O) yielded the chloro-sulfide 31 and some 37, both in low yields. The product of the addition of 24 to 1-methylcyclohexene was transformed into the trio1 32. Silyl ethers of allylic alcohols reacted with 24 only at room temperature, yielding, after desilylation, isomer mixtures 33 and 34, and pure 35. Much higher yields were achieved for the addition of (thio)sulfenyl halides yielding halogeno-disulfides. Good diastereoselectivities were only obtained with 21, its cyclohexylidene-protected analogue, and 22, and this only in the addition to styrene (+ 36, 37, 38), to (E)-disubstituted alkenes (+ 46, 48, 49a/b, 50a/b, 53), and to trisubstituted alkenes (+ 47,51,52,54,55). Other monosuhstituted alkenes (+ 4145) and (Z)-hex-2-ene (+ 49c/d, 50c/d) reacted with low diastereoselectivities. Where structurally possible, a stereospecific trans-addition was observed; regioselectivity was observed in the addition to mono-and trisubstituted alkenes and to derivatives of ally1 alcohols. The absolute configuration of the 2-chloro-disulfides was either established by X-ray analysis (47a) or detcrmined by transforming (LiAlH,) the chloro-disulfides into known thiiranes (Scheme 5 ) . Thus, 37,48, and the mixture of 49a/b and 50a/b gave the thiiranes 56,61, and 64, respectively, in good-to-acceptable yields (Scheme 5 ) . Harsher conditions transformed 56 into the thiols 57 and 58. Similarly, 61 gave 62. The enantiomeric excesses of these thiols were determined by GC analysis of their esters obtained with (-)-camphanoyl chloride. Addition of 21 to ([(E)-hex-2-enyl]oxy}trimethylsilane, followed by LiAIH, reduction and desilylation, gave the known 66 (63 %, e.e. 74%). The diaslereoselectivity of the addition of 21 to trans-disubstituted and trisubstituted alkenes is rationalized by assuming a preferred conformation of the (thio)sulfenyl chloride and destabilizing steric interactions with one of the alkene substituents, while the diastereoselectivity of the addition to styrene is explained...

show abstract

Click-Chemie: diverse chemische Funktionalität mit einer Handvoll guter Reaktionen

Kolb¹,

2001

View full text Add to dashboard Cite

Betrachtet man die in der Natur am häufigsten vorkommenden Verbindungen, so fällt auf, dass die Bildung von Kohlenstoff‐Heteroatom‐Bindungen gegenüber der von Kohlenstoff‐Kohlenstoff‐Bindungen deutlich bevorzugt ist. Da zum einen Kohlendioxid die Basisverbindung der Natur ist und andererseits das Medium natürlicher Reaktionen zumeist Wasser ist, überrascht dies sicherlich nicht. Nucleinsäuren, Proteine und Polysaccharide sind polymere Kondensationsprodukte kleiner Untereinheiten, die durch Kohlenstoff‐Heteroatom‐Bindungen verknüpft sind. Sogar die etwa 35 Baueinheiten, aus denen diese essentiellen Verbindungen bestehen, enthalten nicht mehr als sechs aufeinander folgende C‐C‐Bindungen, sieht man einmal von den drei aromatischen Aminosäuren ab. Mit der Natur als Vorbild richteten wir unser Interesse auf die Entwicklung leistungsfähiger, gut funktionierender und selektiver Reaktionen für die effiziente Synthese neuartiger nützlicher Verbindungen sowie kombinatorischer Bibliotheken mittels Heteroatomverknüpfungen (C‐X‐C). Diese Synthesestrategie nennen wir „Click‐Chemie“. Click‐Chemie ist durch eine Auswahl einiger weniger nahezu idealer Reaktionen charakterisiert, mit all ihren Grenzen und Möglichkeiten. In diesem Beitrag werden zum einen die strengen Kriterien, die Reaktionen erfüllen müssen, um die Bezeichnung „Click‐Chemie“ zu verdienen, definiert, zum anderen werden Beispiele für molekulare Strukturen gegeben, die mit dieser spartanischen, aber dennoch leistungsfähigen Synthesestrategie leicht hergestellt werden können.

show abstract

Thiiranium‐Ionen als Reaktionszwischenstufen

Cited by 61 publications

References 56 publications

Cyclization reactions in the chemical ionization spectra of bifunctional alkyl phenyl ethers

Cyclization reactions in the chemical ionization spectra of bifunctional alkyl phenyl ethers

Glycosylsulfenyl‐ und (Glycosylthio)sulfenyl‐halogenide (Halogeno‐ bzw. Halogenothio‐(1‐thioglycoside)): Herstellung und Umsetzung mit Alkenen

Click-Chemie: diverse chemische Funktionalität mit einer Handvoll guter Reaktionen

Contact Info

Product

Resources

About