Methylenation with Bis iodozincio methane

Aldehydes were methylenated by bis(iodozincio)methane (4) [18]. Commercially available Nysted reagent 3 was also effective for this transformation in this case, an addition of catalytic amount of BF3 Oetj improved the yield (Table 8.1) [20]. 

Methylenation reactions of ketones at ambient temperature with 4 required addition of titanium salt to obtain the good yield. As shown in Table 8.2, 2-dodeca-none was treated with bis(iodozincio)methane (4) in the presence of various titanium salts. As titanium chloride, [S-TiClj, which had been prepared from titanium (IV) chloride and hexamethyldisUane by following Girolami s procedure, [21] was shown to be the most effective. Hermes and Girolami s report corrected the errors in the Naula and Sharma s result Naula and Sharma had reported that TiClj was formed from the reaction of titanium(IV) chloride and hexamethyldisUane 

RCHO (1.0 mmol), dizinc (l.Oor 2.0 mmol), and additive were mixed in THF. 

3 TiClj AlClj (Aldrich), a-TiCl, (Aldrich), and TiCl2(Aldrich). Isolated yields. 

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