Sulfilimines

Aziridines have been prepared stereospecifically by the nucleophilic addition of the nitrogen residue to alkenes <80T73). Introduction of the nitrene is accomplished readily via a Michael-type addition with free diphenylsulfilimine (Scheme 12), and where a chiral sulfilimine is used the chirality is transferred to the aziridine with optical yields in excess of 25%. 

The great reactivity of the sulfurane prepared by this procedure toward active hydrogen compounds, coupled with an indefinite shelf life in the absence of moisture, makes this compound a useful reagent for dehydrations,amide cleavage reactions, epoxide formation, sulfilimine syntheses, and certain oxidations and coupling reactions. 

Optically active sulfoximines (133) and sulfilimines (134) may be converted to optically active sulfoxides12,142. 

Addition of nitrogen to the lone pair of sulfoxides or of oxygen to the lone pair of sulfilimines is quite common and leads to sulfoximines (see also Section II.G). Such reactions have been reviewed12,13. 

Abstract The photoinduced reactions of metal carbene complexes, particularly Group 6 Fischer carbenes, are comprehensively presented in this chapter with a complete listing of published examples. A majority of these processes involve CO insertion to produce species that have ketene-like reactivity. Cyclo addition reactions presented include reaction with imines to form /1-lactams, with alkenes to form cyclobutanones, with aldehydes to form /1-lactones, and with azoarenes to form diazetidinones. Photoinduced benzannulation processes are included. Reactions involving nucleophilic attack to form esters, amino acids, peptides, allenes, acylated arenes, and aza-Cope rearrangement products are detailed. A number of photoinduced reactions of carbenes do not involve CO insertion. These include reactions with sulfur ylides and sulfilimines, cyclopropanation, 1,3-dipolar cycloadditions, and acyl migrations. 

Sulfur-stabilized ylides underwent photodriven reaction with chromium alkoxy-carbenes to produce 2-acyl vinyl ethers as E/Z mixtures with the E isomer predominating (Table 22) [ 121-123]. The reaction is thought to proceed by nucleophilic attack of the ylide carbon at the chromium carbene carbon followed by elimination of (CO)5CrSMe2. The same reaction occurred thermally, but at a reduced rate. Sulfilimines underwent a similar addition/elimination process to produce imidates or their hydrolysis products (Table 23) [ 124,125]. Again the reaction also proceeded thermally but much more slowly. Less basic sulfilimines having acyl or sulfonyl groups on nitrogen failed to react. 

Table 23 Photo-driven reactions of sulfilimines with alkoxycarbenes...

There are related reactions in which the sulfur is at the sulfoxide or sulfilimine oxidation level. Another example of the addition-cyclization route involves a-haloesters, which react to form epoxides by displacement of the halide ion. 

On the other hand, deprotonation of cycloadduct 76 with sodium hydride in acetonitrile at 0°C afforded cyclic sulfilimine 78, the so-called 1,2-azathiabenzene derivative, together with a spiro compound 79 (see Equation (21) and Table 11) <1999TL1505>. 

In addition the structure of the 1,2-azathiabenzene 78 was also confirmed by chemical evidence as shown in Scheme 10. Protonation of 78a (R1 = R2 = Me) with 70% perchloric acid yielded the corresponding cyclic amino sulfonium salt 82a in 87% yield, but not the starting sulfonium compound 76a, suggesting predominance of sulfilimine structure 78a rather than cyclic sulfonium ylide stmcture 80a. Thus, compound 78 could be recognized as the first example of a 1,2-azathiabenzene having sulfur at a bridgehead position. A proposed mechanism for the formation of 78 and 79 is shown in Scheme 9. The most acidic proton adjacent to sulfur in 76 is deprotonated with... 

Cyclic sulfilimines are considered useful reagents in organic synthesis <00JOC8086 03JOC9574>. The chemistry of cyclic sulfilimines has been studied extensively since the... 

As depicted in the following scheme, in the presence of sodium iodate and pyridine, several 5,6-dihydroxylated benzofuran derivatives were synthesized via an oxidation-Michael addition of P-dicarbonyl compounds to catechols in a one-pot procedure <06TL2615 06JHC1673>. A novel additive Pummerer reaction of 2-benzo[fc]furan sulfilimines with carbon nucleophiles derived from P-dicarbonyl compounds was also employed to the synthesis of 2,3-disubstituted benzo[b]furans <06TL595>. 

The furazan ring can be constructed by the one-pot reaction of iV-(5,5-dimethyl-3-oxocyclohexenyl)-.S,.S-diphenyl-sulfilimine 272 with isopentyl nitrite <2006SC2087> and also by a one-pot procedure from sulfinimines 273, without isolation of the nitroso intermediates, in refluxing toluene (Scheme 71) <2002T10073>. 

The reaction of the thiolated PVC with Chloramine T carried out and the structure ( ) of the resultant polymer was examined (1 ). In the case of phenyl-thioether, the sulfilimine structure (2) was mainly produced accompanied with, in part, the sulfenamide structure (8,) binded to the main chain with N atom, the case of allyl thioether derivative containing C=C moiety in the pendent group, the sulfilimine (9) formed rearranged exclusively in Claisen type to the sulfenamide structure (10) connected to the main chain with S atom. 

Though the PECH decomposes to indefinite fragments with n-butyl lithium or sodium hydride in THF at room temperature, it reacts with sodium methoxide with liberation of Cl in which the -elimination of hydrogen chloride predominates instead of nucleophilic substitution. For instance, PECH in DMSO was reacted with double the molar quantity of sodium methoxide at room temperature for 24 h to give the unsaturated polyether (DS 92.3%,v(C=C) 1630,5 (=CH2) 795 cm" ) after purification by dissolution(DMF)-precipitation (H20) technique. A similar unsaturated polyther was obtained by the pyrolysis of the sulfilimine 13 (110-130°C) but not of sulfoxide 12 (100-150°C). When the polymer 26, was heated to 90°C, the absorption of C=C and =CH2 decreased and a new absorption at 1720 cm appeared and increased. This is explained as a result of [3.3] sigmatropic rearrangement of to afford including C=CH2 and C=0 structure as shown in equation 7. 

A set of sulfoxides, tosylated sulfilimines, and sulfinate esters were separated using five different commercially available glycopeptides CSPs, namely ristocetin A, tei-coplanin, TAG, vancomycin, and VAG, and seven mobile phases (three NP, two RP,... 

In 1953 Djerassi and Engle showed that stoich. RuOyCCy oxidised several sulfides to the corresponding sulfones [236]. Sulfilimines (R R S=NR ) were oxidised to sulfoximes R R S(=0)=NR by RuO /aq. Na(IO )/CH2Cl2 [432] oxidation of thianthrene-5-oxide with RuO /aq. Na(IO )/CCyO°C gave thianthrene-5,5-dioxide. Comparisons were made between the behaviour of RuO, CrO Cl and [MnO ] for these reactions, and 0-atom transfer with a possible intermediacy of [RuO ] was postulated [433]. Oxidations of RSPh to the sulfoxides and sulfones by stoich. RuOyaq. CH CN were studied a concerted mechanism may be involved for these and for similar oxidations by [RuO ] and [RuO ] " (Fig. 1.12) [434]. 

Treatment of various 2-aminopyridines and of 1-aminoisoquinoline with dimethyl sulfide and N-chlorosuccinimide gives the corresponding salt which on deprotonation with base provides a sulfilimine (e.g. 98) (76JCS(P1)2166>. Oxidation of the latter with m-chloroperben-zoic acid gives the corresponding nitroso heterocycle (Scheme 85). 

Alkyl-halogenide konnen auch durch Reaktion mit Diphenylsulfilimin und reduktive Spaltung der N-Alkyl-sulfilimine in primare Amine (z. B. Benzylamin) umgewandelt werden1. 

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