A low-valent titanium generated in situ from Ti(O-i-Pr)(4), Me(3)SiCl, and Mg powder in THF reacted with aryl- and alkyl-sulfonamides of aryl and alkyl amines in a reductive N-S/S-O/S-C bond cleaving pathway to provide the corresponding amines and hydrocarbons (and thiols) derived from the sulfonyl moiety. The reagent could also cleave sulfonates to the corresponding alcohols.

A low-valent titanium species derived in situ from Ti(O-i-Pr)(4), Me(3)SiCl and Mg powder in tetrahydrofuran reacted with epoxides to selectively provide less hindered alcohols via a homolytic ring-opening of epoxides, in which the intermediate β-titanoxy radical intramolecularly abstracted a hydrogen atom from an alkoxy moiety in the titanium complexes.

No abstract

No abstract

Abstraction in β-Titanoxy Radical Intermediates. -A new method for the synthesis of less hindered alcohols via homolytic ring opening of epoxides is described. Mechanistic studies indicate an intramolecular hydrogen abstraction from the Ti-isopropoxy moiety. The addition of an external hydrogen atom source is therefore not required and furthermore allows for a stereoselective conversion of bicyclic epoxides (IX) to give the corresponding anti-configured products (X). Functionalities such as acetal, alkene and silyl ether groups are tolerated under the reaction conditions. -(KAWAJI, T.; SHOHJI, N.; MIYASHITA, K.; OKAMOTO*, S.; Chem. Commun. (Cambridge) 47 (2011) 27, 7857-7859, http://dx.