Complex sentence: In addition, aryl substituted imines are also great substrates for HCN additions, affording very high levels of enantioselectivity, while alkyl substituted imines do not react with HCN enantioselectively, affording products with an enantiomeric excess less than 60%.
Split into simpler sentences: In addition, aryl substituted imines are also great substrates for HCN additions, affording very high levels of enantioselectivity. However, alkyl substituted imines do not react with HCN enantioselectively, affording products with an enantiomeric excess less than 60%.