Preparation of enantiomerically pure derivatives of (3-amino-1,2-dicarba-closo-dodecaboran-1-yl)acetic acid

The enantiomerically pure N- and C-protected derivatives of planar-chiral (3-amino-1,2-dicarba-closo-dodecaboran-1-yl)acetic acid (>99% ee) have first been obtained in good yields via a combination of HPLC separation and synthetic procedures. Assignment of absolute configuration of the carborane fragments has been made based on the X-ray diffraction data of diastereoisomeric derivatives of (S)-amino acids. (C) 2018 Elsevier B.V. All rights reserved.