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Metallocarbenes Fischer-Tropsch type

We should emphasize that Fischer-Tropsch and Schrock type of carbenes are extreme representations of metal carbenoids [17-21]. Furthermore, representation of the metal-carbene bonds in terms of singlet and triplet carbenes is just a convenient way to describe these bonds. For example, both types of metallo-carbenes can be explained on the basis of a singlet carbene fragment very strong it-back donation would lead to the Schrock-type of metallocarbene, while no back donation or a weak n-back donation corresponds to the Fischer-Tropsch type of metallocarbene. Of course, it is also possible to understand both types of metallo-carbenes solely on the basis of the triplet carbene fragment. Once again, the use of either both models or only one of them to understand the nature of the M-carbene bond is just a matter of preference. [Pg.23]

Scheme 2.6 Schematic presentation of the whole spectrum of metal-carbene bonds in metallocarbenes. Here, we based our presentation on the Fischer-Tropsch type of metallo-carbene. Scheme 2.6 Schematic presentation of the whole spectrum of metal-carbene bonds in metallocarbenes. Here, we based our presentation on the Fischer-Tropsch type of metallo-carbene.
Thus, the relatively weak Schrock-type oilandrelatively strong Fischer-Tropsch type of metallocarbenes are more attractive for the C-H, C=C, and C=C bond alkylation by diazocarbenes. The aforementioned delicate balance can be achieved by utilizing combination of... [Pg.36]

Scheme 2.5 Schematic presentation of M-carbene bonding in Fischer-Tropsch and Schrock types of metallocarbenes. Scheme 2.5 Schematic presentation of M-carbene bonding in Fischer-Tropsch and Schrock types of metallocarbenes.

See also in sourсe #XX -- [ Pg.23 , Pg.36 ]




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Metallocarbenes

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