1,3,5-Trithiane metallation

The procedure described here provides a convenient route to aldehydes with trithiane serving as an inexpensive, masked carbonyl group.2-4 The reaction is limited, however, to the use of primary alkyl halides, aldehydes, and ketones for elaboration of the carbon chain through attack on the metallated trithiane. Examples of aldehydes synthesized by this method are given in Table I. 

As typical examples of complexes with bidentate RS(CH2) SR and tridentate [RS(CH2) ]2S we may quote here a series of mononuclear Ru compounds which have been prepared and characterized by Chatt et aV Another example of a tridentate ligand is trithiane, which forms complexes with Ag1 and Hg11.9,10 More complexes are given in a review concerned with chelating dithioether complexes of d% metal ions.11. 

The methylations of l,3-dilithio-5,7-dimethyl-2,4,6,8-adamantane and of 1,3,5,7-tetrathiacyclooc-tane tetraanion- are of theoretical value only. 1,3,5-Trithiane and both mono- and 2,4,6-trialkyl-substituted derivatives have been metallated - with n-butyllithium and alkylated - with reactive alkylating agents such as primary alkyl iodides or bromides and benzyl bromide (Scheme 73, entries a and b). The metallation of monoalkylated trithianes occurs at one of the two unsubstituted sites and leads eventually to the product having both substituents in the equatorial position. - Thus the high equatorial preference for lithium in 2-lithio-l,3-dithiane is also present in 2-lithio-2-methyl-l,3,5-trithiane. Mer-... 

Trithiane, S3(CH2)3 a chair-shaped molecule like cyclohexane, forms many metal complexes. Two silver compounds have layer structures based on the 6-gon net. In both structures Ag is tetrahedrally coordinated, the fourth ligand (X in Fig. 3.23(a)) being H2O in Ag(trithiane)C104. H2O and 0 of NOJ in Ag(tri-thiane)N03. H2O (JCS A 1968 93). Silver tricyanmethanide, Ag[C(CN)3], has a... 

Bond angles C-S-C close to 100° are found in cyclic molecules based on strain-free 6-rings. All those studied have the chair conformation examples include l,4-dithiane/ 1,3,5-trithiane, and hexathia-adamantane. The last compound, S6(CH)4, is structurally similar to (CH2)eN4 and (CH2)6(CH)4. Trithiane forms many metal complexes the structure of S3(CH2)3. AgC104. H2O is mentioned in Chapter 3 (p. 90). 

C—C Bond formation. s-Trithiane has been used very much like 1,3-dithiane (2, 182-187) in organic synthesis 2-3 hojvever, the carbanion derived from this reagent tends to undergo carbenoid decomposition. Metalated trithiane reacts readily with primary halides to give 2-alkyl-s-trithianes convertible into aldehydes, as shown for a preparation of n-pentadecanal 1... 

Trithiane readily forms complexes to both soft and hard metal ions and borderline cases. For complexes where X-ray structural information is available, it appears that utilization of S-donor sites in normal tridentate chelation is never attained often the ligand is involved in the form of a bridging mode linking two or more separate metal centers. In addition, the 1,3,5-trithiane ring retains the chair conformer which it possesses in the free state. 

The tetranuclear iridium cluster [Ir4(CO)4(l,3,5-trithiane)] exists as two isomers, one possessing a bridging carbonyl ligand and the other not. The unbridged isomer is discussed as an intermediate in a merry-go-round isomerization process. The pentanuclear clusters [MIr4(CO)7(/i-CO)2 L(>/ -C5Me5)(/i4-PPh)] (M = Rh, Ir L = CO) have square-pyramidal metal... 

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