Titanocene(II)-promoted desulfurizative tertiary alkylation of 1,3-bis(phenylthio)alk-1-enes and β,γ-unsaturated thioacetals

High Oxidation State Multiple Metal−Carbon Bonds

“…Stable alkylidene complexes of group 4 metals are rare, although titanium alkylidene complexes have been proposed as intermediates in a variety of reactions, according to products obtained upon reaction in the presence of olefins, ketones, solvent CH bonds, alkynes, etc. For example, titanium alkylidene complexes have been generated by treating dithioacetals with Cp 2 Ti(II) reagents, − by decomposing Cp 2 TiRR‘ species, − by thermolyzing tetraalkyls (neopentyl , or trimethylsilylmethyl), or by thermolyzing Cp* 2 Ti(diazoalkane) complexes. , The reader is referred to comprehensive reviews for details. − The few new examples of group 4 complexes, like many high oxidation state alkylidene complexes, often are formed by α hydrogen abstraction in a sterically crowded environment.…”

Applications of stoichiometric transition metal complexes in organic synthesis

“…Takeda has published a few papers exploiting the reactivity of thioacetal groups with titanium() reagents. In the first, 23 1,3-bis(phenylthio)alk-1-enes react with the titanium() reagent Cp 2 Ti[P(OEt) 3 ] 2 (Scheme 8). The proposed titanium carbene intermediate then reacts further, with a tertiary alkyl chloride to produce a new carbon-carbon bond.…”

The Society for Cardiovascular Angiography and Interventions' 27th Annual Scientific Sessions

“…The typical reaction is shown in Scheme . The terminal olefin 48 was obtained by the titanocene(II)‐mediated reaction of the bissulfide 43a with 3‐chloro‐3‐ethylpentane followed by the hydrolysis of the intermediate alkenyltitanium species 49 48. Allylic alcohols and conjugated dienes were obtained by the treatment of the intermediary alkenyltitaniums with aldehydes and alkynes, respectively 49…”