Isolation and Structural Characterization of the Lithium Cyanoorganocuprate Salt [Li(THF)₂{Cu(CN)C₆H₃-2,6-Trip₂}]₂ (Trip = −C₆H₂-2,4,6-i-Pr₃)

Lithium Cyanocuprates: Structural Studies of a Phosphane Adduct of a “Lower‐Order” Lithium Cyanocuprate

“…Spectroscopic studies of lower-order cyanocuprates both in solution [3] and the solid state [4Ϫ7] have shown 1, or aggregates of 1 such as 2, to be the most likely structural motif for these species (Scheme 1). Hence [(Me 2 PhSi) 3 CCu(CN)Li(THF) 3 ] [4] is a monomer (1) in the solid state, whilst [(Me 2 PhSi) 3 CCu(CN)Li(THF) 2 ] 2 , [4] [(C 6 H 3Ϫ 2,6-Trip 2 )Cu(CN)Li(THF) 2 ] 2 [5] (Trip ϭ ϪC 6 H 2 -2,4,6-iPr 3 ), [Me 3 SiCH 2 CuCNLi(OEt 2 ) 2 ] 2 , [6] and [tBuCu(CN)Li-(Et 2 O) 2 ] ϱ [7] are all dimers (2). However, the structure of higher-order cyanocuprates has been the subject of much more controversy with arguments centering on whether the cyanide group remains bound to the copper or not.…”

Synthesis and Characterization of (THF)3Li(NC)CU(C6H3-2,6-Mes2)and Br(THF)2Mg(C6H3-2,6-Trip2) (Mes = C6H2-2,4,6-Me3; Trip = C6H2-2,4,6-i-Pr3): The Structures of a Monomeric Lower-Order Lithi

“…15 The reason for this is not clear. However, Eaborn et al 16 stated that they obtained a dimeric cyanocuprate, [(Me 2 PhSi) 3 CCu(CN)Li(THF) 2 ] 2 , simply by removing the solvent (THF) from the corresponding monomer and then recrystallizing in a different solvent (toluene).…”

Kinetic Reactivity of “Higher Order Cuprates” in SN2 Alkylation Reactions

“…The positive Gilman test of the Lipshutz reagent strongly suggests that RLi species are generated in solution 11. Whereas the species that reacts with Michler's ketone could be 1 c , it would more likely be 1 d ,21 which would easily form from 1 c through the reorganization of the ionic bonds around the lithium atoms. Isomer 1 d is ideally disposed to undergo addition to a ketone through a six‐centered TS typical for an alkyllithium reagent 22.…”