Synthesis of bis(benzoxazole) frameworks chiralized by planar chiral [2.2]Paracyclophane

In this study, a new class of chiral bis(benzoxazole) has been synthesized. The bis(benzoxazole) framework, which has an achiral structure was chiralized by a planar chiral [2.2]paracyclophane moiety. Both enantiomeric forms of the bis(benzoxazole) derivatives were successfully obtained in 99% ee. Even though the starting material was not completely enantiomerically pure, enantiomeric enrichment was afforded by the Horeau principle in the synthesis route. (C) 2021 Elsevier Ltd. All rights reserved.