Neuere Methoden der präparativen organischen Chemie VI Umsetzungen mit <i>N</i>‐Carbonyl‐sulfamidsäurechlorid

Graf, Roderich

doi:10.1002/ange.19680800503

Cited by 84 publications

(4 citation statements)

References 25 publications

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“…KFHF acts as both nucleophile and buffer, in this case preventing nucleophilic replacement of entire sulfonyl group. [58] Sulfonimidoyl chlorides and sulfamoyl chlorides [59] with electron withdrawing substituents on nitrogen [60] are very similar in their reactivity to sulfonyl chlorides (vide supra) and can be converted to the corresponding fluorides by treatment with saturated aqueous KFHF (Figure 7 A,B). When electron donating groups are present on nitrogen, bifluoride is not reactive enough, giving low yields under standard conditions.…”

Section: Sulfur(vi) Fluoride Exchangementioning

confidence: 99%

Sulfur(VI) Fluoride Exchange (SuFEx): Another Good Reaction for Click Chemistry

et al. 2014

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Aryl sulfonyl chlorides (e.g. Ts-Cl) are beloved of organic chemists as the most commonly used S(VI) electrophiles, and the parent sulfuryl chloride, O2 S(VI) Cl2 , has also been relied on to create sulfates and sulfamides. However, the desired halide substitution event is often defeated by destruction of the sulfur electrophile because the S(VI) Cl bond is exceedingly sensitive to reductive collapse yielding S(IV) species and Cl(-) . Fortunately, the use of sulfur(VI) fluorides (e.g., R-SO2 -F and SO2 F2 ) leaves only the substitution pathway open. As with most of click chemistry, many essential features of sulfur(VI) fluoride reactivity were discovered long ago in Germany.6a Surprisingly, this extraordinary work faded from view rather abruptly in the mid-20th century. Here we seek to revive it, along with John Hyatt's unnoticed 1979 full paper exposition on CH2 CH-SO2 -F, the most perfect Michael acceptor ever found.98 To this history we add several new observations, including that the otherwise very stable gas SO2 F2 has excellent reactivity under the right circumstances. We also show that proton or silicon centers can activate the exchange of SF bonds for SO bonds to make functional products, and that the sulfate connector is surprisingly stable toward hydrolysis. Applications of this controllable ligation chemistry to small molecules, polymers, and biomolecules are discussed.

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Section: Sulfur(vi) Fluoride Exchangementioning

confidence: 99%

Sulfur(VI) Fluoride Exchange (SuFEx): Another Good Reaction for Click Chemistry

et al. 2014

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“…KFHF wirkt in diesem Fall sowohl als Nukleophil als auch als Puffer, wodurch es den nukleophilen Austausch der gesamten Sulfonylgruppe verhindert. [58] Sulfonimidoylchloride und Sulfamoylchloride [59] mit elektronenziehenden Substituenten am Stickstoff [60] [61] Ein Überblick über die umfangreichen biomolekularen Daten, die von der Baker-Gruppe erhoben wurden, ist an anderer Stelle zu finden. [62] Einige der von Baker und anderen entwickelten Verbindungen, welche die affinitätsgeführte Aktivierung von Sulfonylfluoriden zum Aufbau von kovalenten Bindungen mit Aminosäureresten von Proteinbindungsstellen ausnutzen, sind in Abbildung 8 dargestellt.…”

Section: Synthese Von Sulfonylfluoriden Aus Chloridenunclassified

Schwefel(VI)‐fluorid‐Austausch (SuFEx): Eine weitere gute Anwendung für die Click‐Chemie

et al. 2014

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Arylsulfonylchloride (z. B. Ts‐Cl) sind die am häufigsten eingesetzten SVI‐Elektrophile in der organischen Synthesechemie, und auch die Stammverbindung, das Sulfurylchlorid (O2SVICl2), wurde zur Synthese von Sulfaten und Sulfamiden genutzt. Allerdings wird die gewünschte Halogenidsubstitution oftmals durch die Zersetzung des Schwefelelektrophils in SIV‐Spezies und Cl− verhindert, denn die SVI‐Cl‐Bindung ist äußerst reduktionsanfällig. Mit Schwefel(VI)‐fluoriden (z. B. R‐SO2‐F und SO2F2) verläuft die Umsetzung hingegen ausschließlich über den Substitutionsweg. Wie es bei der Click‐Chemie zumeist der Fall ist, wurden viele entscheidende Aspekte der Reaktivität von Schwefel(VI)‐fluoriden vor langer Zeit in Deutschland entdeckt.6a Überraschenderweise gerieten diese außerordentlichen Arbeiten in der Mitte des 20. Jahrhunderts ziemlich abrupt aus dem Blickfeld. In diesem Aufsatz versuchen wir, dieser Chemie neues Leben einzuhauchen. Insbesondere stützen wir uns dabei auch auf John Hyatts unbeachtet gebliebene Veröffentlichung über CH2CH‐SO2‐F aus dem Jahr 1979.98 Wir tragen mehrere neue Beobachtungen bei, einschließlich dem Befund, dass das ansonsten sehr stabile Gas SO2F2 eine exzellente Reaktivität unter den richtigen Umständen aufweist. Wir zeigen auch, dass Protonen oder Siliciumzentren den Austausch von S‐F‐Bindungen gegen S‐O‐Bindungen aktivieren können und dass der Sulfat‐Konnektor überraschend hydrolysestabil ist. Anwendungen dieser kontrollierbaren Ligationschemie auf kleine Moleküle, Polymere und Biomoleküle werden diskutiert.

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“…IR: 3620 ± 2400w, 3000m, 2940s, 2860m, 1720s, 1465w, 1455m, 1440m, 1410w, 1380m, 1355m, 1345w, 1325w, 1300m, 1285m, 1275m, 1260m, 1240w, 1195w, 1185m, 1175m, 1160m, 1140 ± 1110m, 1075s, 1055w, 1035m, 1025s, 990m, 945w, 905w, 870w, 810w, 705w, 660w, 615w. Ethyl (À)-(2E,5R)-5-Hydroxydec-2-enoate (14). Ethyl(diethoxyphosphinyl)acetate (1.16 ml, 5.78 mmol, 1.2 equiv.)…”

Section: (T) Ci-ms: 120 ([M Nh 4 ]mentioning

confidence: 99%

“…Therefore, the OH group of 13 was first quantitatively THP-protected (THP tetrahydro-2H-pyran-2-yl) by treatment with cat. TsOH ¥ H 2 O (Ts tosyl p-toluenesulfonyl) and dihydro-2H-pyran in CH 2 Cl 2 at room temperature to give 20, then the ester function was totally For the planned diastereoselective amination of the (E)-olefinic C 10 framework by intramolecular conjugate addition of a carbamate group (Scheme 4), the key intermediate 14 was transformed into the d-(carbamoyloxy) ester 11 according to the standard procedure of Graf [14]: by treatment of the d-hydroxy ester 14 with chlorosulfonyl isocyanate in CH 2 Cl 2 for 1 h at À 788 and subsequent hydrolysis of the chlorosulfonyl group, the carbamoylation of the homoallylic group was achieved in 94% yield. In the next step, cooled 0.1m t BuOK in dry THF was added dropwise at 08 to 0.1m d-(carbamoyloxy) ester 11 in THF, and the mixture was kept at 08 for 2.5 h. In accordance with the related studies made by Hirama and co-workers [15], the thermodynamically controlled, base-catalyzed aza-Michael cyclization of 11 to the 6-membered oxazinone system 22 succeeded with 80% chemical yield and remarkably To preserve the ethyl ester function of 22, the cleavage of the carbamate ring was first attempted under anhydrous biphasic conditions with carbonate (K 2 CO 3 , Na 2 CO 3 , Cs 2 CO 3 ) and hydroxide (KOH, NaOH) bases in various dry organic solvents (THF, DMF, MeCN, and CH 2 Cl 2 ), but this did not meet with success.…”

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confidence: 99%

Enantioselective Entry to the Homalium Alkaloid Hoprominol: Synthesis of an (R,R,R)‐Hoprominol Derivative

Ensch¹,

Hesse²

2003

Helvetica Chimica Acta

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The diastereoselective synthesis of the N-and O-protected hoprominol derivative (R,R,R)-6 is described. The building up of the bicyclic O-silylated and di(N-tosylated) asymmetric scaffold 6 succeeded by convergent preparation of the two basic chiral azalactam units 7a and 7b and their subsequent iterative linking by a known method (Scheme 5). Both 4-alkyl-hexahydro-1,5-diazocin-2(1H)-ones 7a and 7b were prepared from the chiral b-amino acid portions 10a and 10b, respectively, by application of a set of reactions (e.g., N-alkylation of 10a,b and Sb(OEt) 3 -assisted cyclization of the resulting open-chain intermediates) already known. In comparison with the total syntheses of homaline (1) and homoprine (2), the newness of the described synthesis lies in the asymmetric approach to the difunctionalized fatty acid derivative 10b starting from (À)-(S)-malic acid (9) (Schemes 3 and 4). Key step in the preparation of 10b was the diastereoselective amination of the optically pure a,b-unsaturated d-hydroxy homoallylic ester 14 via conjugate intramolecular aza-Michael cyclization of the acylic d-(carbamoyloxy) intermediate 11.Introduction. ± Isolated from the leaves of the New Caledonian plant Homalium pronyense Guillaum. (Flacourtiaceae) [2], the four Homalium alkaloids homaline (1), hopromine (2), hoprominol (3), and hopromalinol (4) constitute a small family of optically active natural products characterized by a unique bis-eight-membered lactam structure incorporating a spermine (5) backbone (Fig.). The structures of the Homalium alkaloids were elucidated in the seventies by Pais and co-workers [3], and the correctness of the proposed formulae was confirmed by several total syntheses since then.A single-crystal X-ray analysis [4] as well as manifold asymmetric syntheses [5] [6] allowed the determination of the absolute (S,S)-configuration of the major alkaloid homaline (1). In a preceding paper [1], we presented a new, potent synthetic entry to the Homalium scaffold that enabled us to prepare (AE)-homaline (1) and (À)-hopromine (2) and, hence, to determine the absolute configuration of the natural hopromine (2) as being (R,R). Since, hitherto, all the syntheses of the remaining, unsymmetrically substituted parent molecules hoprominol (3) and hopromalinol (4) are nonstereospecific [7], the absolute configurations of the alkaloids 3 and 4 are still unknown. Hereafter, we now wish to report the application of our previously described synthetic strategy for building up the bicyclic Homalium core by the preparation of the N-and O-protected (R,R,R)-hoprominol precursor 6 (Fig.), with the higher aim of elucidating the yet-undefined configuration of the natural product (À)-homprominol (3).

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Neuere Methoden der präparativen organischen Chemie VI Umsetzungen mit N‐Carbonyl‐sulfamidsäurechlorid

Cited by 84 publications

References 25 publications

Sulfur(VI) Fluoride Exchange (SuFEx): Another Good Reaction for Click Chemistry

Sulfur(VI) Fluoride Exchange (SuFEx): Another Good Reaction for Click Chemistry

Schwefel(VI)‐fluorid‐Austausch (SuFEx): Eine weitere gute Anwendung für die Click‐Chemie

Enantioselective Entry to the Homalium Alkaloid Hoprominol: Synthesis of an (R,R,R)‐Hoprominol Derivative

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