The Dynamic Covalent Chemistry of Amidoboronates: Tuning the rac /rac Ratio via the B-N and B-O Dynamic Covalent Bonds.

Invited for this month's cover is the group of Anna J. McConnell and Christian Näther from Christian-Albrechts-Universität zu Kiel, Germany. The cover picture shows an amidoboronate puzzle divided into four quarters that represent four possible amidoboronates.

The Dynamic Covalent Chemistry of Amidoboronates: Tuning the rac /rac Ratio via the B-N and B-O Dynamic Covalent Bonds.

Amidoboronates were prepared as a mixture of up to three isomers (rac , meso and rac ) from the reductive coupling of N-aryl iminoboronates with either cobaltocene or decamethylcobaltocene in acetonitrile. The interconversion of rac and rac isomers via rearrangement of their dynamic covalent B-N bonds was investigated in solution by redissolving isolated crystals. The aniline para substituent and catechol within the amidoboronates tuned the rac /rac ratio; the rac isomer predominated for amidoboronates based on pyrocatechol, ranging from a ratio of 0 : 1 with electron-withdrawing Cl substituents to 0.