Asymmetric solid-phase alkylation of ketones immobilized via SAMP hydrazone analogue linkers.

The preparation and application of new solid supports with chiral linkers, analogues of SAMP hydrazine on solid-phase, are described. The supports were used for immobilization of ketones (diethylketone, cyclohexanone, 4- tert-butylcyclohexanone), and diastereoselective alkylation of formed chiral ketone hydrazones. The enantiomeric purities of cleaved alpha-alkylated chiral ketones ranged from 10 to 73%. The use of chiral lithium amides for metalation of hydrazones of t-butylcyclohexanone increased the enantiomeric excess of the alkylated product by 25-47%.