Thietane 1,1-dioxides substitution reactions

The following compounds have been obtained from thiete 1,1-dioxide Substituted cycloheptatrienes, benzyl o-toluenethiosulfinate, pyrazoles, - naphthothiete 1,1-dioxides, and 3-subst1tuted thietane 1,1-dioxides.It is a dienophile in Diels-Alder reactions and undergoes cycloadditions with enamines, dienamines, and ynamines. Thiete 1,1-dioxide is a source of the novel intermediate, vinylsulfene (CH2=CHCH=SQ2). which undergoes cyclo-additions to strained olefinic double bonds, reacts with phenol to give allyl sulfonate derivatives or cyclizes unimolecularly to give an unsaturated sultene. - Platinum and iron complexes of thiete 1,1-dioxide have been reported. 

Although the yields of the above reactions are high and the procedure is simple186, there are some apparent disadvantages the selection of the sulfene substituents R1 and R2 is limited, depending on the availability of the sulfonyl chloride precursors the cycloaddition leads to a mixture of cis- and trans-substituted thietane dioxides the cycloaddition reaction is reversible202 and several further transformations are necessary if a dioxide without 3-lV-substituent is required. 

Simple unsaturated sulfides cannot be used in place of enamines in cycloaddition reactions with sulfines leading to thietane dioxide derivatives. " Alkyl, vinyl, and cycloalkylvinyl sulfides, which carry a C=C double bond, are considerably less nucleophilic than the enamines and thus do not partake in cycloadditions to sulfene. But when the more electrophilic methylsulfonyl sulfene is used in association with an unsaturated sulfide substituted with a strong electron donating alkylamino group, the formation of thietane dioxides 72 is successful. 

Paquette et alf have shown that the well-known reaction of sulphenes with vinyl amines to form thietan dioxides is amenable to asymmetric induction. The reaction of the parent sulphene with electronegatively substituted carbonyl compounds can follow two courses (see Scheme 1),... 

The reaction of Af,Af-dimethyl-( )-styrylamine (73) with a halogen-substituted methanesulfonyl chloride allowed the first stereoselective formation of the halogenated thietane 1,1-dioxide 74, which then could be converted to the corresponding thiete sulfone 75 via a Cope elimination of the corresponding AT-oxide. ... 

The susceptibility of the thiete 1,1-dioxides to nucleophilic addition reactions can be utilized to produce 3-substituted thietane derivatives. For example, the thus easily attainable 3-cyano and 3-nitroalkyl-substituted derivatives could be reduced to the 3-aminomethylthietanes ° (Eq. 61). 

In addition to the unsubstituted sulfene itself, the various substituted sulfenes used in the preparation of thietane 1,1-dioxides are listed in Table 4. Although the usual method for generating the sulfenes is by treatment of a methanesulfonyl chloride with triethylamine, sulfenes have been obtained by the reaction of phenyl-methanesulfonyl fluoride with phenyllithium, by treatment of a-chloro-ethanesulfinic acid with refluxing triethylamine,by treatment of 4-nitro-phenyl or 2-chloro-4-nitrophenyl, esters of arylmethanesulfonic acids with potassium t-butoxide or 2,6-dimethylpyridine, respectively, by treatment of diazoalkanes with sulfur dioxide" (e.g., to give 146) and by thermolysis of a Diels-Alder adduct of sulfene." ... 

Treatment of cis- or tra 5-2,4-diphenyl thietane 1,1-dioxide with t-butoxy-magnesium bromide or ethylmagnesium bromide gives sultines (cyclic sulfin-ates) in which the stereochemistry is preserved (e.g., 171) and cyclo-propanesulfinic acids (e.g., 172). Bases such as hydroxide ion or triethyl-amine cause ring-opening of 3-amino substituted thietane sulfones via an elimination reaction as shown for The... 

Additions of the Michael type of nucleophiles to the carbon-carbon double bond of thiete 1,1-dioxides to give 3-substituted thietane 1,1-dioxides occur readily. The addition of hydrogen has been discussed in Section A. Nucleophiles include cyanide, the anion of nitroethane, the lithium salt of r-butyl o-tolyl sulfone, dimethylamine, cyclohexylamine, ethoxide, and hydrogen sulfide. The reaction is exemplified by the synthesis of 278. Additions to 3-chloro-2H-thiete 1,1-dioxide most likely proceed by an addition-elimination mechanism an example is shown for the addition of the anion of dimethylmalonate to give 279. The replacement of a 3-morpholinyl group by a 3-A methyl-A-phenylamino group in thiete 1,1-dioxide is another example of addition-elimination. An addition of ethoxide with elimination of p-nitrophenyl anion may occur with 268 (Ar = / -N02C6H4). " Addition of bromine via N-bromo-succinimide to the double bond of 4-phenyl-2H-thiete 1,1-dioxide occurs only in 1.5% yield. ... 

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