Fully enzymatic resolution of chiral amines:: Acylation and deacylation in the presence of Candida antarctica lipase B

A fully enzymatic methodology for the resolution of chiral amines has been demonstrated. Candida antarctica lipase B (CaLB)-catalyzed acylation with N-methyl- and N-phenylglycine, as well as analogues having the general formula R-1-XCH2CO2R2 (R-1 = Me, Ph; X = O, S) afforded the corresponding enantioenriched amides, which were subsequently enzymatically hydrolyzed. Surprisingly, CaLB also proved to be the catalyst of choice for this latter step. The heteroatom in the acyl donor profoundly influences both the enzymatic acylation and deacylation; the 0-substituted reagents performed best with regard to enantioselectivity as well as reaction rate in synthesis and hydrolysis.