On enantioselective deprotonation: synthesis and crystal structure of a chiral amidolithium tetrahydrofuran complex

Enantioselective base (R, R')-bis(1-phenylethyl)amidolithium was crystallized from THF/hexane. X-ray crystallography characterized it as a bis-THF-solvated cyclic dimer which takes an a conformation that maximizes methylithium contacts. This contradicts earlier justifications of its enantioselectivity in enolizations of cyclic ketones.