Tungsten complex boryl

Important advances in the field of C-H bond activation have involved the photochemical reactions of boryl complexes such as Cp W(CO)3(Bcat) (98, cat = 1,2-02-3,5-Me2C6H2). Transient species derived from these complexes efficiently activate the C-H bonds of alkanes and arenes (see Alkane Carbon-Hydrogen Bond Activation), and they can convert hydrocarbon solvents into alkylboronate esters (equation 27). Experimental and theoretical studies have shown that these reactions proceed via a boron-assisted, a-bond metathesis see a-Bond Metathesis) pathway involving back donation of electron density from the tungsten atom to a formally unoccupied p orbital centered on the boryl ligand. ... 

Table 2 Selected spectroscopic and structural parameters for molybdenum and tungsten boryl complexes ...

Fig. 6 Base-stabilized boryl complexes of molybdenum and tungsten...

Fig. 7 Molybdenum and tungsten boryl complexes of the type Tp (CO)2W 2-BWCHsR7 ...

Fig. 8 Tungsten boryl complexes featuring oxygen substituents, 6.14-6.18...

The boryl system Tp (CO)2Mo /72-B(Et)CH2(C6H4Me-4), (6.13, Fig. 7), has been synthesized by the reaction of the hydroborating agent Et2BH with the Fischer carbyne complex Tp (CO)2Mo=C(C6H4Me-4) [48,49] a number of related tungsten complexes have been synthesized which are discussed below (vide infra). 

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