Structure and Reactivity of a Sulfoximine-Stabilized Chiral Dilithiocarbanion

Article abstract of DOI:10.1002/hlca.19970800717

The synthesis and X-ray analysis of a racemic dilithiated S-ethyl-N-methyl-S-phenylsulfoximine cluster 2 with N,N,N',N'-tetramethylethane-1,2-diamine (TMEDA) as coordinating solvent is presented. The lithium complex 2 consists of a mixed tetrameric mono- and dilithio salt. Unexpectedly, a separation of the enantiomers in mono-and dilithiated antipodes with respect to the chirality center on the S-atom is observed. Dilithiation of S-ethyl-N-methyl-S-phenylsulfoximine (1) affords a chiral dinucleophile which undergoes highly regio- and stereoselective alkylation reactions with bis-electrophiles.