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The role of Cp2Ti(H)Cl in the reactions of Cp2TiCl with trisubstituted epoxides has been investigated in a combined exptl. and computational study. Although Cp2Ti(H)Cl has generally been regarded as a robust species, its decompn. to Cp2TiCl and mol. hydrogen was found to be exothermic (ΔG = -11 kcal/mol when the effects of THF solvation are considered). In lab. studies, Cp2Ti(H)Cl was generated using the reaction of 1,2-epoxy-1-methylcyclohexane with Cp2TiCl as a model. Rapid evolution of hydrogen gas was measured, indicating that Cp2Ti(H)Cl is indeed a thermally unstable mol., which undergoes intermol. reductive elimination of hydrogen under the reaction conditions. The stoichiometry of the reaction (Cp2TiCl:epoxide = 1:1) and the quantity of hydrogen produced (1 mol per 2 mol of epoxide) is consistent with this assertion. The diminished yield of allylic alc. from these reactions under the conditions of protic vs. aprotic catalysis can be understood in terms of the predominant titanium(III) present in soln. Under the conditions of protic catalysis, Cp2TiCl complexes with collidine hydrochloride and the titanium(III) center is less available for "cross-disproportionation" with carbon-centered radicals; this leads to byproducts from radical capture by hydrogen atom transfer, resulting in a satd. alc. (2-methylcyclohexan-1-ol). [on SciFinder(R)] CAPLUS AN 2020:290383(Conference; Meeting Abstract; Online Computer File)