Sulfanyl compounds

Fluorinated sulfanyl compounds are of no commercial interest. Detailed toxicological investigations are rare. Table 21 lists a number of prescreening results. 

Isomerization-RCM strategy, which was successfully applied to the synthesis of 1,4-diazocines and 1,4-oxazocines on catalysis with 77 (see Sections 14.06.3.4.1 and 14.06.4.4), afforded the benzothiazocine dioxide 139 from the sulfone 138 in high yield (Equation 33) <2004TL9171>. As for the sulfanyl compounds 134 (X = S) (Scheme 15), the substrate 138 (X = S) was inert under isomerization-RCM conditions. 

Purin-2-ol and -8-0I are less reactive than the 6-hydroxy derivatives which react to give the corresponding 6-sulfanyl compound, e.g-... 

A high-yield conversion of guanosine and 2 -deoxyguanosine into the corresponding 6-sulfanyl compounds, e.g. 17, in a two-step, one-flask reaction via a 6-pyridyl intermediate has been reported. 

Substitution of chlorine in the pyridine part is also possible. Thus, with ammonium hydrogen sulfide in water at 120 °C, 6-benzyl-7-chloro-5-methylpyrido[2,3-r/]pyrimidine-2,4-diamine is converted into the corresponding 7-sulfanyl compound.238... 

A small amount of pyrido[3,4-<7]pyrimidin-4(3//)-one is obtained by treatment of pyri-do[3.4-rf]pyrimidine-4-thiol with chloroacetic acid and sodium carbonate in water.364 The main product is the 4-(carboxymethyl)sulfanyl compound (13%). 

Treatment of 2,7-diphenylpyrido[4,3-d]pyrimidin-5(6//)-one with phosphorus pentasul-fide in pyridine gives the sulfanyl compound,527 and 6-ethylpyrido[4,3-(/]pyrimidin-5(6//)-one yields the corresponding 5-thione.533... 

A large part of the derivatives of the diazinodiazines 1-12 consists of hydroxy derivatives or the corresponding tautomeric oxo form. As the position of the tautomeric equilibrium is not known in many cases, these compounds will be shown throughout in the hydroxy form, regardless of their representation in the original literature. The same applies to thioxo or sulfanyl compounds although special mention is made in those instances where the position of the tautomeric equilibrium has been studied more closely. 

Pyrimido[5,4-c]pyridazin-8-ol is transformed into the corresponding sulfanyl compound by reaction with phosphorus pentasulfide.42... 

With R4 = CH(Et)CH2OH ring opening occurs to give a dihydrooxazole (see Section 1.4.6.2.1.2.).54 d As with secondary aliphatic amines (see footnote b), the 3-sulfanyl compounds also react with aromatic amines to yield the corresponding 3-anilinobenzo[e]-l,4,2-dithiazines (see also refs 63 and 64). 

The chemistry for RAFT is illustrated in Scheme 3. The RAFT process is the newest of the living-radical processes and is reported not to have the limitations of the two previously described systems [45], It is essentially a degenerative transfer process in which a polymer chain (P ), initiated with an azo or peroxy initiator, reacts with a (thiocarbonyl)sulfanyl compound, S=C(Z)-S-R, to release R, an alkyl radical which can go on to initiate another polymer chain. Another propagating chain (Pm ) can subsequently react with P -S-C(Z)=S to release P which can go on to add more monomer. This cycle then repeats itself to produce polymer. 

The cyclization of 1,2-dicarbonyl compounds with aldehydes in the presence of NH4OAC to give imidazoles was employed in a combinatorial study that compared conventional and microwave heating in the preparation of a library of sulfanyl-imidazoles (Scheme 15). The study employed an array of expandable reaction vessels that could accommodate a pressure build-up system for heating without loss of volatile solvents or reagents. A 24-membered library of imidazoles (48 and 49) was prepared in 16 min instead of the 12 h required using conventional heating [45]. 

Among /1-thiosubstituted organophosphorus compounds bearing chiral groups, phosphono methyl thiazolines (Sect. 2.2.1, Scheme 8) and o-sulfanyl aryl phos-phonamides or phosphinoxides (Sect. 3.3, schemes 20 and 21) have already been mentioned. As a complement to this, some recent synthesis of non racemic /1-sulfinyl phosphines and phosphonates and thiazolidinyl phosphonates are reported below. Moreover, some chiral )8-thio-substituted phosphines have been used as metal ligands in asymmetric catalysis and are listed in Sect. 5.3. 

Sulfanyl derivative 285 treated with active methylene compounds provides corresponding 1,2-dinucleophilic adducts 286-289 in good yields (Scheme 38) <2001PS(174)255>. 

The chemical synthesis of the Amanita toxins has presented several problems, in particular those related to the formation of the sulfur bridge. The latter has been explored with model compounds.[2 31 It has been found that the synthesis of the (sulfanyl)indole moiety can be achieved by reacting an indole compound with an alkanesulfenyl chloride. A model tryptathionine compound has been prepared by reacting A-acyl-L-cysteine and /V-acyl-L-tryptophan in the presence of A-chlorosuccinimide in glacial acetic acid at room temperature.[4] The sulfanylation reaction has been subsequently exploited for the selective chemical modification of tryptophan residues in proteins using 2-nitrophenylsulfenyl chlorideJ5 ... 

The p-sulfanyl amides 28 are synthesized from N-protected amino acids 24 via amino alcohols 25, which are converted into (5-acetylsulfanyl amides 26 by a Mitsunobu reaction. The (5-amine disulfide 27 is subsequently coupled with a variety of carboxylic acids, followed by reduction with tributylphosphine in aqueous THF in the presence of pyridine to produce the free thiol 28 (Scheme 5).1211 Detailed experimental procedures for these compounds have not been reported. 

The performances of the acyl groups were estimated from a dynamic thiolester system, generated from thiocholine 2 (choline analog) and five thiolesters 1A-E as shown in Scheme 5. All thiolester compounds were prepared from 3-sulfanyl-propionic acid 4, in order to keep all acyl components soluble in aqueous solution at neutral pH. After mixing one equivalent of each thiolester 1A-E and five equivalents of thiocholine 2 in neutral deuterated buffer solution, the exchange... 

Reduction of T [l-(2-nitrophenyl)-l//-pyrrol-2-yl]sulfonyl -acetone or -1-phenylethan-l-one with sodium borohy-dride and 5% palladium on carbon, a reagent known to convert aromatic nitro compounds to hydroxylamines, triggers intramolecular interaction and gives pyrrolo[l,2- ][3,l,6]benzothiadiazocine derivatives 90 (Equation 11 <2001MI1405, 2004T8807>). This method was further successfully applied to the reductive cyclization of 2- [l-(2-nitrophenyl)-17/-pyrrol-2-yl]sulfanyl acetonitrile. 

Widder, S., Sabater Liintzel, C., Dittner, T, Pichenhagen, W. (2000). 3-sulfanyl-2-methylpentan-l-ol, a new powerful aroma compound. J. Agric. Food Chem., 48, 418-423. 

Halopurines are valuable intermediates in the synthesis of amino-, hydroxy-, or sulfanyl-substi-tuted purines and the C NMR chemical shifts of selected compounds are summarized in Table 11. 

Active compounds in this series react readily with nucleophiles containing primary amino and sulfanyl groups. 

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