Sulfur diimide reactions

Of particular interest is the reaction of 5,5-disubstituted sulfur diimides (188) with oxalyl chloride in dilute solution in the presence of triethylamine. The l,2,5-thiadiazole-3,5-dione (189) was formed in almost quantitative yield (72LA(759)107). 

Thionyl imide, HNSO, is a thermally unstable gas, which polymerizes readily. It can be prepared by the reaction of thionyl chloride with ammonia in the gas phase. Organic derivatives RNSO have higher thermal stability, especially when R = Ar. The typical synthesis involves the reaction of a primary amine or, preferably, a silylated amine with thionyl chloride. A recent example is the preparation of FcNSO (Fc = ferrocenyl) shown in Eq. 9.8. In common with other thionylimines, FcNSO readily undergoes SO2 elimination in the presence of a base, e.g., KO Bu, to give the corresponding sulfur diimide FcNSNFc. 

The photolysis of 10.3a in pentane or the reaction of 10.3a with PPhs generate the corresponding sulfur diimide ArN=S=NAr (Ar = 2,4- Bu2-6-MeC6H2) as the major product, presumably via the intermediate formation of the thionitrosoarene." By contrast, thermolysis in arene solvents results in ring closure to give the 2,1-benzisothiazole 10.4 and the corresponding aniline."... 

Several methods for the preparation of unsymmetrical sulfur diimides RN=S=NR have been developed. One approach involves the addition of a catalytic amount of an alkali metal to a mixture of two symmetrical sulfur diimides, RN=S=NR and RT8i=S=NR. A second method makes use of alkali-metal derivatives of [RNSN] anions.Eor example, derivatives in which one of the substituents is a fluoroheteroaryl group can be prepared by the reaction of the anionic nucleophile [RN=S=N] with pentafluoropyridine. Sulfur diimides of the type RN=S=NH (R = 2,4,6- Bu3C6H2S) have also been prepared. "... 

The most important fragmentation reactions of sulfur diimides occur with polynuclear metal carbonyls, e.g., M3(CO)i2 (M = Fe, in... 

Redox reactions occur between sulfur diimides and reagents... 

The chemistry of the sulfur diimides (65) has been investigated in some detail, because such compounds might act as S—N or N—S—N transfer agents and thus allow access to novel heterocyclic systems. They are generally prepared by the action of sulfur tetrafluoride on primary amines.90 Some of their reactions parallel those of the /V-sulfinylamines— for example, the... 

The unsaturated four-membered P2N2 ring is also stabilised by the formation of diadducts with Lewis acids, which are surprisingly formed in the reaction of Ph2PCl with bis(trimethylsilyl)sulfur diimide with Gads or AICI3 [eqn... 

Reaction of 2-aminobenzamides with A, A( -bis(p-toluenesulfonyl)sulfur-diimide (Tos—N=S —N —Tos) gives betaines 278 via the acyclic intermediates 280. Compound 278 (R = R = H) is a yellow crystalline solid (Vco 1640 cm ) which is hydrolyzed to compound 281. Meerwein alkylation gives benzothiadiazinium tetrafluoroborates 282. ° ° ... 

N-Arylamidines act as 1,5-dinucleophiles towards sulfur dichloride, N-sulfinyltosylamide and bis(N-tosyl)sulfur diimide. The products are 1,2,4-benzothiadiazines (Scheme 14) (73ZOR2038, 68LA(715)223), and in the case of sulfur dichloride, chlorination of the aromatic ring also occurs. 1,2,4-Benzothiadiazines can also be prepared from N-arylamidines by reaction with sulfenyl chlorides or disulfides in the presence of NCS. Thus N-phenylben-zamidine and benzenesulfenyl chloride give the 1,2,4-benzothiadiazine (182) (78CC1049). 

Thiadiazines can also be prepared from [3 + 3] condensations involving sulfur diimides. Thus reaction of bis(lV-tosyl)sulfur diimide (69TL4117) with 1,3-diaminopropane gives the thiadiazine (18). Bis(trimethylsilyl)sulfur diimide reacts with CSI to give a 1,3,2,4,6-dithiatriazine (74CB1,.74ZN(B)799) (Scheme 27). 

Established methods for making 1,2,6-thiadiazines that have no 1,1-dioxide group include reactions of (i) sulfur diimides with malonyl chlorides and 1,3-diaminopropanes, (ii) sulfur dichloride with 1,3-diaminopropanes, and (iii) thionyl chloride with N.N-l,5-dinucleophiles such as 1,3-diaminopropanes or /3-amino a,/3-unsaturated aldimines and ketimines to give 5-oxides (79MI1 84MI1). 

The preparation of the sulfur analogue Li[PhS(NSiMe3)2] (9) involves treatment of N,N -bis(trimethylsilyl)sulfur diimide with phenyllithium (Eq. 5). A 2 1 adduct with diethylether (10) is isolated when the reaction is carried out in this solvent [43] ... 

ENE REACTIONS Alkylaluminum halides. Bis(methoxycarbonyl)sulfur diimide. Chlorine oxide. 8-Phenylmenthol. Tin(IV) chloride. 

The reaction of AT-sulfinyl dienophiles with 1,3-dienes yields 3,6-dihydrothia-zine 1-oxides (compare the corresponding reactions with sulfur diimides. Sect. 3.1), which can be ring opened with carbon nucleophiles to yield allylic sulfoxides ready to undergo the ME rearrangement. The seminal paper on this chemistry by Weinreb appeared in 1984 (Scheme 57) [67,140]. 

The reactions of Fc-NHj with thionyl chloride or sulfur dichloride lead to ferrocenyl thionylimide, Fc-NSO, and diferrocenyl sulfur diimide, Fc(NSN)Fc, respectively (Scheme 5-10) [68],... 

Reaction of 214 and silyl- and stannyl-substituted sulfur diimide affords derivatives 215 and 216, respectively (Scheme 75) (79CB1372). 

It is worthwhile mentioning that N02 is desoxygenated to NO in its photochemical reaction with [CsHsMnfCO NOjPFg yielding [CsHsMn (NO)2]n, n > 1 367). A very surprising reaction is the formation of the thionitroso complexes (14 and 15). While (14) results from the photochemical reaction of the sulfur diimide RN=S=NR with Fe(CO)5, (15) is obtained by desoxygenation of RNSO with Fe2(CO)9 365>. 

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