Iron isocyanides carbonyls

In this contribution we describe facile, high-yield syntheses of the series of zerovalent iron isocyanide complexes Fe(CO)5 (CNC6H3Me2-l,3)n ( n = 1-5). The starting material is iron pentacarbonyl, and cobalt(II) chloride is used as a catalyst to achieve the stepwise replacement of carbonyl groups by 2-isocyano-l,3-dimethylbenzene.4,9... 

These expressions have been applied to the series isocyanide and carbonyl complexes of rhenium(I) tr ns-[ReL2(dppe)2]" (L = CNR, CO) [19, 20] and of nitrile and carbonyl compounds of iron(II) tmns-[FeL2(depe)2]2+ (L = NCR, CO) [35], and the Es and /J values of the corresponding trons- ReL(dppe)2 " and trans- FeL(depe)2 " " centers, which are given in Table 9, have been discussed earlier. 

A recent review has highlighted the extensive and interesting chemistry of metal isocyanide complexes.1 Although synthetic procedures are varied, a vast number are based on substitution in metal carbonyl complexes by isocyanides. Such procedures are, however, not always successful. This is especially so in cases where multiple substitution of CO is required, as in the syntheses of homoleptic isocyanide complexes. Many of the inherent difficulties are illustrated by the reaction of iron pentacarbonyl with isocyanides. 

Allyl complexes (pseudo-rotations, dynamic NMR studies, 1, 416 with tungsten carbonyls and isocyanides, 5, 688-689 rc-Allyl complexes with Cr, 5, 305 with Cr(II), 5, 300 with Cr(III), 5, 300 and cyclodextrins, 12, 789 in enyne carbometallation, 10, 328 with rhodium, 7, 220-221 (j-Allyl complexes, with iron, 6, 98 5-Allyldiisopinocampheylboranes, in asymmetric allylboration, 9, 198... 

Bis[iV,iV -di(2-pyridyl)-imidazol-2-ylidene]aurate(I) tetrafluoroborates, preparation, 2, 292-293 Bis[iV,iV -di(2-pyridyl-methyl)-imidazol-2-ylidene]aurate(I) tetrafluoroborates, preparation, 2, 292-293 Bis(diselenolate) complexes, dinuclear iron compounds, 6, 242 Bis(dithiolene) compounds, in tungsten carbonyl and isocyanide complexes, 5, 644 Bis(enolato) complexes, with bis-Cp Ti(IV), 4, 589 Bis(enones), in reductive cyclizations, 10, 502 Bis(ethanethiolato) complexes, with bis-Cp Ti(IV), 4, 601 Bis(ethene)iridium complexes, preparation, 7, 328-329 -Bis(fluorenyl)zirconocene dichlorides, preparation,... 

Iron carbonyl complexes with As, Sb, Bi donor ligands, 6, 57 with boron, 6, 7 cyanides and isocyanides, 6, 15 Fe3(CO)i2, 6, 260... 

Iron Chemistry of NS3-Carbonyl, Nitrosyl and Isocyanide Complexes... 

KETONES 1,3-Benzodithiolylium perchlorate. Benzyl(chloro)bis(triphenyl-phosphine)palladium. Chlorobis-(cyclopentadienyl)hydridozirconium. Iron carbonyl. Manganese(ll) iodide. Silver acetate. Thionyl chloride. Tosylmethyl isocyanide. Tri-p-carbonylhexacarbonyldiiron. 

Pentacarbonyl iron is fairly inert to substitution reactions, and attempts to prepare Fe(CO)5- (CNR) (n = 1-5) by the direct reaction of Fe(CO)5 with isocyanides in Carius tubes has produced only the complexes Fe(CO)s (CNR) (n = 1 and 2). The products were obtained as mixtures that required separation. Other syntheses, including photochemical and trimethylamine N-oxide-promoted displacement of carbonyl groups, or other means, give the same products in variable yield. Procedures based on diiron nonacarbonyl and triiron dodecacarbonyl have produced similar results. The only zero-valent iron complex Fe(CO)5 (CNR) where n > 2 is the complex Fe(CNR)5 prepared either by metal vapor synthesis techniques or by sodium amalgam reduction of iron(II) bromide in the presence of isocyanide. ... 

Other isocyanate syntheses that have recently been reported include several well-known reactions. One area which has attracted considerable attention is that of the direct production of isocyanates by the carbonylation of nitro-arenes. Both mono- and di-isocyanates are claimed to have been produced using various catalysts palladium, rhodium, and iron compounds often being cited. Other preparative reactions for isocyanates which have appeared in the literature include the acid catalysed hydrolysis of isocyanide dihalides and the reaction between alkyl halides and alkali-metal cyanates, although the latter has been given a modern flavour by the use of a polymer-supported reagent. ... 

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