B-H activation

The carbonylation of (Cp )(77S-C2B9H11)TiMe resulted in an unusual B-H activation, generating novel complexes containing linked carborane-alkoxide ligands.30 However, dicarbollide analogs of the constrained-geometry complex,... 

It is no coincidence that the first X-ray structure analysis of a transition metal-boryl complex [8] was made on the iridium complex jac-[IrH2(BC8Hi4)(PMe3)3] (2) [9] derived from the B—H activation of the 9-borabicyclo[3.3.1]-nonane (9-BBN)... 

Compounds of Type D represent a hitherto unknown coordination pattern in borane and heteroborane chemistry that results from an unexpected B,H- activation. 

Mahan, B. H.. Activated complex theory of bimolecular reactions, J. Chem. Educ., 51, 709-711 (1974). 

Metal induced B-H activation of semi-sendwich Cp Rh-, Cp Ir- (p-cymol)R-, and (p-cymol)Os-complexes containing l,2-dicarba-c/oxo-dodecaborane(12)-dichalcogenate ligand 01IZV1444. 

Also noteworthy are some alkylidenes that exemplify rare reactivity for metal hydrides. The first is the cyclic carbene complex 565, the formation of which is itself unusual, proceeding as it does from the interaction of Bp Rh(CO)(py) (566) and methyl iodide. This is proposed to involve the oxidative addition of Mel and subsequent migratory insertion of CO, though at what stage the B-H activation occurs remains to be determined. More significant, however, is that on heating to 45 °C, 565 irreversibly evolves into the alkyl complex 567 via a rare reverse a-hydride migration onto the alkylidene carbon (Scheme 55, Section II-D.2). 

Thus, our initial goal was to develop new synthetic procedures to allow high yield selective synthesis of vinylborazine. Since our previous work - has demonstrated that transition metal reagents, similar to those widely employed in organic and organometallic chemistry, may be used to catalyze a variety of transformations involving B—H activation reactions, we investigated the use transition metals to catalyze the alkyne-addition and olefin-substitution reactions of borazine. As a result we found, as indicated below, that B-vinyl... 

Cp Rh[S2C2(BioHio)] reacted with ethynylferrocene in a 1 1 ratio by inserting into one of the Rh-S bonds, followed by B-H activation, transfer of a hydrogen atom to carbon via rhodium, and formation of an Rh-B bond. The resulting compound 131 was characterized by X-ray structural analysis. 

Alcaraz G, Hehnstedt U, Clot E, Vendier L, Sabo-Etienne S. A terminal borylene ruthenium complex from B-H activation to reversible hydrogen release. J Am Chem Soc. 2008 130 12878-12879. 

Boron Intramolecular, enantioselective hydroboration of the normally unreactive A -het-erocyclic carbene (NHC)-boranes, such as (84), has been attained by B-H activation in the presence of rhodium(I) catalyst and the chiral diphosphine ligand (86). The cyclic boranes (85) thus obtained were of <98% eeP... 

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