Dicarbonyltitanocene is an efficient and highly selective catalyst for alkyne hydroborations by catecholborane and dimethyltitanocene is an efficient and highly selective catalyst for alkene hydroborations. These results contrast the hydroboration chemistry with other early transition metal complexes that simply lead to decomposition of catecholborane to form diborane and parallel the hydroboration chemistry of permethylcyclopentadienyl ...