Thiocarbonyl complexes reactions

The complex also undergoes a variety of addition reactions with reagents such as methyl iodide, hydrochloric acid, benzoyl chloride, and allyl chloride.8 In a reaction similar to that of the decarboxylation of aldehydes, the complex will abstract CS from carbon disulfide to give the irans-thiocarbonyl complex rans-RhClCS[P(C8H6)5]2.9... 

When thiocarbonyl derivatives are treated with an excess of electrophilic carbene complex, alkenes are usually obtained [1333-1336], The reaction is believed to proceed by the mechanism sketched in Figure 4.18, closely related to the thiocarbonyl olefination reaction developed by Eschenmoser [1337], Few examples have been reported in which stable thiiranes could be isolated [1338], The intermediate thiocarbonyl ylides can also undergo reactions similar to those of carhonyl ylides, e.g. 1,3-dipolar cycloadditions or 1,3-oxathiole formation [1338], Illustrative examples of these reactions are given in Table 4.22. 

The complexes are reactive towards nucleophilic as well as electrophilic attack. Attack by alkyl halides yields thioalkylated compounds. Mostly an alkylation at one sulfur atom takes place, but examples of alkylation at both sulfur atoms are known (reactions 1 and 2). The facile sulfur abstraction with PPh3 yielding a thiocarbonyl complex is a nucleophilic reaction (reaction 3). 

B. D. Dombeck, and R. J. Angelici, Electrophilic and Oxidative Addition Reactions of Tungsten Thiocarbonyl Complexes, Inorg. Chem. 15, 2397-2402 (1976). 

Ir(CO)(CS2)(PPh3)2](BPli4). It was formulated as an octahedral species with a rc-bonded CS2 ligand, as in (64). However, when attempts were made to alkylate [Ir(CO)(CS2)(PPh3)2]+ to form the dithioester complex, which should have reacted with acids in an alternative route to the thiocarbonyl complex, the reactions proved unsuccessful. The complex turned out to be... 

Several diatomic ligands similar to CO are worth brief mention. Two of these, CS (thio-carbonyl) and CSe (selenocarbonyl), are of interest in part for purposes of comparison with CO. In most cases, synthesis of CS and CSe complexes is somewhat more difficult than for analogous CO complexes, because CS and CSe do not exist as stable, free molecules and do not, therefore, provide a ready ligand source.Therefore, the comparatively small number of such complexes should not be viewed as an indication of their stability. Thiocarbonyl complexes are also of interest as possible intermediates in certain sulfur transfer reactions in the removal of sulfur from natural fuels. In recent years, the chemistry of complexes containing these ligands has developed more rapidly as avenues for their synthesis have been devised. 

The reactions of coordinated CSj and of thiocarbonyl complexes have been covered in reviews by Bianchini et al. (5) and Broadhurst (i). 

AHf of metal silicides 5.10.3.2.1 Thiocarbonyl complexes formation 5.8.2.13.1 Tin amides reactions with metal carbonyls 5.S.5.4.3 Tin azides reactions with... 

A complex reaction of 4-methylquinoline (187) with thionyl chloride gives a [l,2]dithiolo[3,4-c]quinolin-l-one (189) [88JCS(Pl)3025j initial formation of the thiocarbonyl chloride (188) was proposed, as shown in Scheme 43, and susequent steps probably involved disulfur dichloride formed in situ. 

Some metal carbonyl hydrides react with CO2 to give formate complexes. Reactions involving CS2 give thiocarbonyl and dithioformate complexes ... 

The coordinated thiocarbonyl group more readily undergoes nucleophilic attack on the carbon atom and electrophilic attack on the sulfur atom than does the carbonyl group. Moreover, thiocarbonyl complexes may participate in reactions in which the thiocarbonyl group itself does not change, for example, substitution reactions involving ligands other than CS. 

The associative substitution reactions of metal carbonyls, and the preparations, bonding and reactivity of thiocarbonyl complexes were also reviewed in 1985. 

Cyclopentadienyl Carbonyl and Related Complexes.—Successive attack of CHs and CH3+ on [CpMn(CO)2(N2>] yields the azomethane complex [CpMn(CO>2 N-(Me)=NMe ], which can also be synthesized by oxidation of [CpMn(CO)2 MeN-(H)NHMe ]. Similar nucleophilic and electrophilic attacks on the dinitrogen complex using Ph and H+ gives [CpMn(CO)a N(Ph)=NH ]. The pyrrolyl nitrogen atom of [(> -C4H4N)Mn(CO)3] acts as a donor in the formation of the complexes [(OC)3Mn( -C4H4N)M(CO)2Cp] (M = Mn or Re).i The adducts RsP.CSa (R=Bu or Cy) have been assessed as reagents for the preparation of thiocarbonyl complexes. Unfortunately reactions such as [CpMn(CO)2(as-cyclo-octene)] with R3P,CSa lead mainly to [CpMn(CO)2(PR3)] with very low yields of [CpMn(CO)2(CS)].i ... 

---