# Spherical Amides with C3 Symmetry: Improved Synthetic Approach and Structural/Optical Analysis

## TL;DR

A new method was developed to synthesize spherical amides with C3 symmetry, enabling the production of previously unattainable derivatives and revealing their optical properties.

## Contribution

A one-step cyclization method was introduced to synthesize spherical amides with C3 symmetry and produce N-benzyl and N-allyl derivatives.

## Key findings

- The new method enabled synthesis of N-benzyl and N-allyl derivatives not achievable before.
- Electronic circular dichroism spectra showed the compounds are mirror images.
- The N-benzyl derivative's enantiopure crystal structure was confirmed via X-ray analysis.

## Abstract

A spherical amide with C3 symmetry was synthesized by a one-step cyclization reaction using triphenylphosphine and hexachloroethane as coupling reagents. This method enabled synthesis of N-benzyl and N-allyl derivatives, which could not be obtained by the previously reported method. The optical resolution of each compound was measured, and their electronic circular dichroism spectra revealed that they were mirror images. The high structural symmetry resulted in a higher Δε (molar absorption difference against right or left circular polarization: εL − εR value compared to that of another structural isomer synthesized previously. The absolute structure of the enantiopure crystal of the N-benzyl derivative was determined using the Flack parameter obtained by X-ray crystallographic analysis.