| Abstract
| - The reaction mechanism of Ti-catalyzed hydroboration of olefins has been investigated with the aid of density functional calculations. The Ti−O coordination in a reaction intermediate has been found to promote the hydroboration reaction, leading to the formation of the hydroborated products.
- The B3LYP method of density functional theory is used to study the hydroboration reactionof olefins catalyzed by Cp2Ti(HBcat‘). The favorable pathway is where the active speciesCp2Ti(HBcat‘) initially coordinates an olefin to form a structural intermediate having a five-membered ring with a Ti−H−B bridging unit. B−H bond cleavage then occurs to allow thereductive elimination to form alkylboronate ester as the main product. Calculations showthat from the B−H cleavage species the β-hydride elimination leading to the formation ofside products, vinylboronate ester, is also competitive. Ti−O coordination is found to be themain reason for the lowering of the barrier of reductive elimination to form the main product,alkylboronate ester. The related olefin hydrogenation process has also been studied.
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