A practical synthesis of novel chiral sulfoxide-nitrogen ligands

Novel chiral sulfoxide-nitrogen ligands which are derived from amino alcohols were developed. All of fourteen sulfoxide-nitrogen ligands can be synthesized by three steps without any chiral auxiliary. In addition, every step of the synthesis can be achieved in gram-scale by using the preparation of L9-L12 as examples. These sulfoxide-nitrogen ligands may be applicable to the asymmetric catalytic 1,3-dipolar cycloaddition of azomethine ylide with alkylidene malonate. (C) 2015 Elsevier Ltd. All rights reserved.