212264-35-2Relevant academic research and scientific papers
Cycloaddition and nucleophilic substitution reactions of the monomeric titanocene sulfido complex (η5-C5Me5)2(C5H5N)Ti=S
Sweeney, Zachary K.,Polse, Jennifer L.,Andersen, Richard A.,Bergman, Robert G.
, p. 7825 - 7834 (1998)
The titanocene sulfido complex Cp*2(py)Ti=S (1, py = pyridine) reacts reversibly with terminal alkynes to give the thiametallacyclobutenes Cp*2Ti(SC(R)=CH) (R = H (2), Ph (3), Tol (4), TMS (5)). Complex 1 also reacts with alkyl halides to give products derived from formal 1,2-addition across the titanium-sulfur bond. Treatment of 1 with allyl halides results in the formation of Cp*2Ti(X)SCH2CHCH2 (X = Cl (10), F (16), Br (17), I (18)). Reaction of 1 with alkyl-substituted allyl chlorides showed that displacement of the halide anion occurs with S(N)2' regiochemistry. A kinetic study of the conversion of 1 to 10 is consistent with a mechanism in which pyridine dissociation from the metal center precedes reaction of allyl chloride with the Cp*2Ti=S fragment. The S(N)2' regiochemistry of the reaction is explained by postulating coordination of the halogen atom to the metal center in the reaction transition state. Complex 1 also reacts with allyl tosylate, but labeling experiments show (in contrast to the allyl chloride reaction) that substitution of the tosylate functionality occurs via a S(N)2 pathway. Heterocycles formed from the reaction of 1 with α,β- unsaturated aldehydes were also isolated and characterized.
