Diastereoselective electrophilic substitution of γ-oxy-substituted benzyllithiums

Reductive lithiation of alkoxy-substituted benzyl methyl ethers and connection with cross-coupling reactions

“…Furthermore, a satisfactory yield was obtained coupling triflate 19 with C 6 H 13 MgBr in the presence of 10 mol% of Fe(acac) 3 in THF/NMP ( Table 2, entry 2), under reaction conditions recently described by Fü rstner and co-workers. 9…”

Reductive Lithiation and Multilithiated Compounds in Synthesis

“…The simultaneous presence of a carbanionic and a heteroanionic functional group is responsible for several interesting features of these intermediates, most probably as a result of the ability of these functionalities to coordinate intramolecularly [17] by a complex-induced proximity effect (CIPE) [18]. As an example, reductive lithiation of diastereoisomeric mixtures of dioxanes (14) afforded intermediate diorganometals (15) epimerized at the benzylic carbon (as determined by D 2 O quenching) which, by reaction with carbon electrophiles, afforded the corresponding 3-aryl-3-substituted propanols (16), with satisfactory yields and good diastereoselectivities (Scheme 12.4) [20,21]. Gleason and coworkers recently reported on the application of the reductive lithiation of sulfur-containing heterocycles to the stereoselective generation of Eand Z-disubstituted amide enolates.…”