Nozaki-Oshima methylenation

Nozaki, Oshima, and Takai reported in 1978 that the reagent prepared from diio-domethane, zinc, and titanium(IV) chloride was effective for the methylenation of ketones [12]. In this procedure, a reagent was prepared by mixing diiodomethane (3.0 equiv.), zinc dust (9.0 equiv.), and titanium(IV) chloride (1.0 equiv.) in THF for 30 min at 25 °C. The ketone substrate (1.0 equiv.) was then added to the prepared reagent. Other metal halides were also examined (Scheme 5.5), but none of them gave better results than titanium) IV) chloride. 

The system CH2Br2-Zn-TiCl4 can also be used for methylenation of ketones. K. Takai, Y. Hotta, K. Oshima, and H. Nozaki, Tetrahedron Letters, 2417 (1978). 

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