A-Sulfonylimine

In the initial report by Corey and Chaykovsky, dimethylsulfonium methylide (2) reacted smoothly with benzalaniline to provide an entry to 1,2-diphenylaziridine 67. Franzen and Driesen reported the same reaction with 81% yield for 67. In another example, benzylidene-phenylamine reacted with 2 to produce l-(p-methoxyphenyl)-2-phenylaziridine in 71% yield. The same reaction was also carried out using phase-transfer catalysis conditions.Thus aziridine 68 could be generated consistently in good yield (80-94%). Recently, more complex sulfur ylides have been employed to make more functionalized aziridines, as depicted by the reaction between A -sulfonylimine 69 with diphenylsulfonium 3-(trimethylsilyl)propargylide (70) to afford aziridine 71, along with desilylated aziridine 72. ... 

A-Sulfonylimines as useful synthons in stereoselective synthesis of heterocycles 97MI40. 

Scheme 10.17 Additions of ZnEtz to A-sulfonylimines with binaphthylthiopho-sphoramide ligand.

Scheme 10.19 Additions of ZnEt2 to A-sulfonylimines with (17 ,27 )-cyclohex-anediamine-derived thiophosphoramide ligand.

Clerici and Porta reported that phenyl, acetyl and methyl radicals add to the Ca atom of the iminium ion, PhN+Me=CHMe, formed in situ by the titanium-catalyzed condensation of /V-methylanilinc with acetaldehyde to give PhNMeCHMePh, PhNMeCHMeAc, and PhNMeCHMe2 in 80% overall yield.83 Recently, Miyabe and co-workers studied the addition of various alkyl radicals to imine derivatives. Alkyl radicals generated from alkyl iodide and triethylborane were added to imine derivatives such as oxime ethers, hydrazones, and nitrones in an aqueous medium.84 The reaction also proceeds on solid support.85 A-sulfonylimines are also effective under such reaction conditions.86 Indium is also effective as the mediator (Eq. 11.49).87 A tandem radical addition-cyclization reaction of oxime ether and hydrazone was also developed (Eq. 11.50).88 Li and co-workers reported the synthesis of a-amino acid derivatives and amines via the addition of simple alkyl halides to imines and enamides mediated by zinc in water (Eq. 11.51).89 The zinc-mediated radical reaction of the hydrazone bearing a chiral camphorsultam provided the corresponding alkylated products with good diastereoselectivities that can be converted into enantiomerically pure a-amino acids (Eq. 11.52).90... 

A sulfonylimine that is formed in situ as a reactive intermediate by interaction of the corresponding aminosulfonyl chloride and triethylamine has proved to be a popular cycloaddition reagent in the synthesis of 1,1-thiazetidines. 

In contrast to the sulfinylimines, the sulfonylimines are used only at a low temperature. Nagai et have studied the reaction of a sulfonylimine with enamines that do not have any reactive hydrogen atoms in the molecule ( Type C enamine). The cyclic product may be produced via a two-step mechanism in which a zwitterionic intermediate (168) occurs (Eq. 34). The Me... 

Oxaziridination of bridged bicyclic A -sulfonylimine 97 with OT-chloroperbenzoic acid (MCPBA), in the presence of K2CO3, affords OTr/o-compound 98 in high yields and 60% de (Equation 8) <1997JOC3625>. 

Diazo(trimethylsilyl)methane reacts with A-sulfonylimines derived from aldehydes to give 2-(trimethylsilyl)aziridines in good yield and with high cis-stereo-... 

The 2-aroylaziridines (303), on thermolysis, provide aroylazomethine ylides which undergo [3 + 2] cycloadditions with various dipolarophiles. Whereas imines are normally inert to dipole synthons, Lown and Landberg reported that the polarized A -sulfonyl-a-acylimines afford initially the 1-sulfonyl-4,5-diacylimidazolines (304) which undergo cyclodehydration (Paal-Knorr reaction) to the furo[3,4-fi ]imidazolines (305) (Scheme 57). A further variant with other substituted A-sulfonylimines (R1 = 4-ClC6H4S02) and sequential amination affords the l,5-dihydropyrrolo[3,4-. 

The [Z + Z] cycloaddition reactions of various 4-dialkylamino-3-butyn-2-ones 102 with substituted phenyl isothiocyanates 103 provide access to a series of thietimines 104 in moderate yields <2001SL361, CHEC-III(2.07.9.2)415>. Likewise, cycloaddition of A-sulfonylimines 105 with alkynyl ethers affords functionalized 2-azetines 106 in a quantitative yield (Scheme 54) <1991ZOB1389>. 

He M, Bode JW (2005) Catalytic synthesis of y-lactams via direct annulations of enals and A-sulfonylimines. Qrg Lett 7 3131-3134... 

The syntheses of chiral 3-substituted sultams 159 and 161 have been achieved through the asymmetric hydrogenation of their corresponding cyclic A -sulfonylimines 157 and 160 by making use of the Pd/bisphosphine complex (S)-SegPhos 158 <07JOC3729>. 

The reaction of simple 277-azirines with heterocumulenes proceeds to give a wide range of heterocyclic adducts. For example, treating 277-azirine-3-methylacrylate 794 with diphenylketene afforded 5-pyrrolin-2-one 795 in 70% yield (Scheme 193) <1997T7089>. A related reaction occurred using A -sulfonylimines to give 1,2,5-thiodiazoles <1996J(P1)1629>. 

The carbon-nitrogen double bond of imine derivatives has been shown to act as a radical acceptor. For example, it was shown that A-sulfonylimines are... 

Keywords aromatic aldehyde, sulfonamide, montmorillonite K-10, microwave irradiation, A-sulfonylimine... 

Thermal Cydoadditions of Trichloromethyl-A -sulfonylimine 6 with Unsymmetrical Dienes... 

The frequency change is evident from the data for s-triazoles in Table II. The wavenumbers of the A-imine functional groups, except for the A-sulfonylimines, are shifted 100 cm-1 to lower values. The mean... 

Cycloadditions. 2-Vinylaziridines can be prepared directly from allyl-dimethylsulfonium bromide and A -sulfonylimines. The sulfonium ylides are generated in situ. 

Another example of the C + C=N" pathway involves the addition of stabilized sulfonium ylides onto A-tosylimines. This is operationally a straightforward procedure under phase-transfer conditions <97TL7225>, and the use of a chiral auxiliary allows the preparation of enantiomerically enriched aziridines, as illustrated by the reaction of A -sulfonylimine 132 with chiral sulfonium propargylide 133 to give the chiral aziridine 134 <97AG(E)1317>. 

The very useful A-sulfonyloxaziridines are conveniently prepared by treating A-sulfonylimines with Oxone in a biphasic solvent system (eq 18). Either bicarbonate or carbonate can be used to buffer this reaction, but reaction is much faster with carbonate, suggesting that the monopersulfate dianion is the oxidizing species (for illustrations of the remarkable chemistry of these oxaziridines, see N-(Phenylsulfonyl)(3,3-dichlorocamphoryl)-oxaziridine). 

On the basis of the above mechanistic assumption, the authors assumed that the p-ICD-amide-p-naphthol dual catalytic system should favor the (5)-aza-MBH product regardless of the nature of the Michael acceptors used and investigated the reaction between A -tosylimine 158 and alkyl vinyl ketone, which is known to provide the (i )-aza-MBH adduct. They developed a new p-ICD-amide (160) and found that an achiral protic additive was capable of inverting the p-ICD and p-ICD-amide (160) catalyzed enantioselective aza-MBH reaction between A -sulfonylimines and MVK/EVK, therefore providing another solution to the enantio-complementarity associated with this family of catalysts (Scheme 2.77). °... 

Startg. aldehyde reacted with N-sulfinyl-/>-toluenesulfonamide at 0° in the presence of 0.5 eqs. BFj-etherate (cf. Synth. Meth. 19, 536) product. Y 79%. This is the first example of the generation of a sulfonylimine from an enolizable aldehyde. F.e.s. M.J. Melnick et al., Tetrahedron Letters 29, 3891-4 (1988). 

A mass spectrometry technique - ESI(- -)-MS(/MS) - has been used to probe solution-phase DABCO-catalysed aza-MBH reactions of A-sulfonylimine (24) with methyl acrylate to give aza-adduct (25). A unique bis-sulfonamide intermediate (26) was intercepted, which - if central to the process - requires a revision of the generally accepted mechanism. A new mechanistic proposal does fit better with some features of aza-MBH reactions. ... 

New chiral phosphorus-olefin bidentate ligands give high ees in the rhodium-catalysed addition of organoboroxines to A -sulfonylimines to give a-substituted... 

A-Sulfinyl aldimines undergo Friedel-Crafts reaction with indoles in up to 99% ee, using a copper(II)-bis(oxazoline) catalyst. An organocatalytic asymmetric aza- 0 Friedel-Crafts alkylation of naphthols with A-sulfonylimines has been developed, giving yields and ees up to 99% 0... 

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