Monomeric lithium and sodium silylbenzyl complexes: syntheses, structures, and C&z.dbd;O bond olefination

Herein we report the syntheses, structures and reactivity studies of two new monomeric alkali metal silylbenzyl complexes stabilised by a tetradentate amine ligand, tris[2-(dimethylamino)ethyl]amine (Me 6 Tren). The two complexes, namely [MR′(Me 6 Tren)] (R′: CH(Ph)(SiMe 3 )) (2-Li: M = Li; 2-Na: M = Na), exhibit significant different coordination modes according to their metal identity (Li: σ-coordination; Na: π-coordination). Reactivity studies of 2-Li and 2-Na reveal that they are efficient in promoting a widely-used class of organic functional group interconversion: C&z.dbd;O bond olefination of ketones, aldehydes and amides, to produce tri-substituted internal alkenes. Herein we report two new monomeric lithium and sodium silylbenzyl complexes, which can efficiently convert C&z.dbd;O bond in ketones, aldehydes and amide into C&z.dbd;C bond, i.e. , conducting olefination.