MOLECULAR-LEVEL CHIRAL DISCRIMINATION AND INDUCTION

The review describes the mechanism of chiral discrimination of racemic amines upon crystallization and the induction of chirality in organic reactions by using them as chiral auxiliaries. In order to form congl omerates, which can be resolved into the two enantiomers upon alternat ive seeding, both formation and packing of 2(1)-columns are essentiall y very important. On the other hand, in order to achieve high efficien cy in resolution through diastereomeric salt formation, which is the m ost practical method, one of a pair of diastereomeric salts derived fr om a racemic amine and an enantiomerically pure resolving agent should at least have two 2(1)-columns and planar boundary surfaces in its cr ystal structure. On the basis of this knowledge, we developed several artificial chiral auxiliaries such as erythro-2-amino-1,2-diphenyletha nol, cis-2-amino-1-acenaphthenol, and cis-2- amino-3,3-dimethyl-1-inda nol. These were found to be very efficient chiral auxiliaries in asymm etric inductions: alkylation of chiral imines, catalytic borane-reduct ion, and alkylation of chiral N-acylated oxazolidinone.