Osmium-nitrogen bond

Protonation of the oximate complexes OsHCl2(ON=CR2) (PTr3)2 produces OsHCl2(=N=CR2)(PTr3)2. An X-ray crystal structure of one derivative shows that it has a short osmium-nitrogen bond distance. This complex reacts with... 

Platinum nanoparticles, preparation, 12, 78 Platinum-nitrogen bonds, in platinacycles, 8, 508 Platinum-osmium carbonyl clusters, characteristics, 8, 420 Platinum-oxygen bonds, in platinacycles, 8, 505 Platinum particles, surface reactivity, 12, 542 Platinum-phosphorus bonds, in platinacycles, 8, 508 Platinum-rhenium carbonyl clusters, characteristics, 8, 420 Platinum(II)-ruthenium(II) binary complexes, preparation,... 

In the asymmetric aminohydroxylation (AA) an olefin is converted into a vicinal amino alcohol by means of an osmium(VIII)-mediated suprafacial addition of a nitrogen and an oxygen atom to the double bond. Like the AD, the AA has been developed by modifying an originally stoichiometric, achiral version. Although the first aminohydroxylations were reported in 1976 [70], the asymmetric catalytic protocol is still underdevelopment [71]. 

Potassium pentachloronitridoosmate(VI) was reported in 1901 by Werner and Dinklage.6 It also is of interest because the nitrogen atom is bonded to only one other atom (osmium), making it a true nitride. 

The AA reaction is closely related to the asymmetric dihydroxylation (AD). Alkenes are enantioselectively converted to protected 3-aminoalcohols (Scheme 1) by syn-addition of osmium salts under the influence of the chirr 1 bis-Cinchona ligands known from the AD process (see Chap. 20.1). As for the AD reaction, a cooxidant is needed to regenerate the active osmium species. But in the AA process the cooxidant also functions as the nitrogen source. Since two different heteroatoms are transferred to the double bond, regioselectivity becomes an important selectivity issue in addition to enantioselectivity. Moreover, chemoselectivity has to be addressed due to the possible formation of the... 

Another example of sulfur abstraction by an osmium nitrido complex occurs in the reaction of [OsNC14]- with (PPh4)NCS to give (Ph4P)2[Os(NS)(NCS)3], in which the thiocyanate groups are thought to be bonded to the metal via nitrogen.265 For reactions of the complex see Scheme 10, p. 563. 

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