Cyclopentadienyl sulfur

Sulfur imides with a single NR functionality, S5NR (6.12), SeNR (6.13) (R = Oct), " SgNH (6.14), ° and S9NH (6.15) ° are obtained by a methodology similar to that which has been used for the preparation of unstable sulfur allotropes, e.g., S9 and Sio. Eor example, the metathesis reaction between the bis(cyclopentadienyl)titanium complexes 6.8-6.10 and the appropriate dichlorosulfane yields 6.14 and 6.15 (Eq. 6.4). °... 

Related sulfur-containing derivatives are formed from the reaction of 49 with 2-methyl-2-propanethiol, cyclo-hexanethiol, and 2-propanethiol in toluene at ambient temperature. The resulting tetrameric cyclopentadienyl thiolato complexes [(if-Cp)Mg(/.t3-SR) ]4 (R = Bu, CgFIn, Pr1) are colorless crystalline solids. Treatment of... 

All studied model compounds can distinctly be divided into three groups (Table VII). The first group is composed of substances in which the sulfur, selenium or cyclopentadienyl anion acts as an anionic center. They exist only in open betaine forms, and their PES do not contain local minima corresponding to cyclic isomers. The second group contains compounds with arsonium cationic and oxide anionic centers and silicon and germanium betaines with arsonium and amide centers. They exist as cyclic isomers and their PES have no local minima corresponding to the open forms. Finally, the third group consists of six studied compounds with phosphonium cationic and oxide or amide anionic centers and arsonium-imide betaine. Their PES have minima for both cyclic and open forms separated by low barriers. 

An unexpected endo selectivity in addition of certain carbon and sulfur nucleophiles to the O, / -unsaturated (arene)ruthenium(II)cyclopentadienyl compound (154) has been reported. This stereochemistry has been compared with that of the 5 n2 reactions but a detailed theoretical approach is yet to be undertaken. ... 

The S5 also occurs in sulfur vapor (7, 24). It is not clear whether the vapor contains cyclopentasulfur or catenapentasulfur, or both. Schmidt 87) proposes that 85 can be prepared from bis-ir-cyclopentadienyl-molybdenum tetrasulfide by reaction with monosulfurdichloride ... 

The successful acylation of ferrocene set off a vigorous research effort that has resulted in the establishment of the present field of metallocene chemistry, ir- Cyclopentadienyl compounds of ruthenium, osmium, manganese, vanadium, and chromium also exhibit certain aromatic-type reactions in varying degrees. These metallocenes thus represent a new class of heterocyclic compounds in which transition metals, akin to nitrogen, oxygen, and sulfur in classical heterocycles, not only are an integral part of the structure but actually participate directly in many reactions. 

Cyclopentadienyl molybdenum-sulfur compounds are useful synthons for the preparation of Mo—M—S (e.g. M = Fe (see Section 36.6.2), Co, Ni) clusters103-108 144 in reactions with metal carbonyls. However, the principal interest in molecules of this class has arisen because of the reactivity of the Mo—S system, primarily in respect of the making and breaking of S—H... 

Organocopper reagents, 207 Organovanadium reagents, 219 By desilylation of vinylsilanes Tetrabutylammonium fluoride, 286 By desulfurization of vinyl sulfides and related sulfur compounds Sodium dithionite, 281 Elimination reactions By dehalogenation Dichlorobis(cyclopentadienyl)-titanium, 102... 

In 2002, the first synthesis and structure of a stable pentathiepin fused to a single cyclopentadienyl ring of ferrocene was performed by the treatment of the corresponding dithiastannole, as a synthetic equivalent of unstable ferrocene-1,2-dithiol with sulfur dichloride <2002TL5825>. Pentathiepin 129 was synthesized as follows (Scheme 29). 

---