Density Functional Theory Investigation of the Reactivity of LiCH2I and Iodomethylzinc Phenoxide Cyclopropanation Reagents with Olefins

We report a systematic density functional theory investigation for the reactions of LiCH 2 I, IZnCH 2 I, iodomethylzinc phenoxide (PhOZnCH 2 I), 2,4,6-F 3 -PhOZnCH 2 I, and 2,4,6-Cl 3 -PhOZnCH 2 I with CH 2 CH 2, trans - CH 3 CHCHCH 3, and PhCHCH 2 . All of the reactions examined displayed similar concerted mechanisms for the cyclopropanation of these reagents. The zinc carbenoids had similar barriers for the cyclopropanation reaction (in the 17−21 kcal/mol range), while the LiCH 2 I carbenoid had a much lower barrier for the cyclopropanation reactions (in the 6−7 kcal/mol range). The properties and chemical reactivity of the carbenoids investigated here were compared to each other and to recent results for the isodiiodomethane (CH 2 I−I) species.