Synthesis and structure of potential Lewis acid–Lewis base bifunctional catalysts: 2-N,N-Diisopropylaminophenylboronate derivatives

Directed ortho-metallation is used to introduce a boron function into N,N-diisopropylbenzamide, resulting in the formation of both borinate and boronate derivatives. N,N-Diisopropylbenzamide ortho-boronate pinacol ester can be reduced with sodium borohydride–TMSCl resulting in N,N-diisopropylbenzylamino ortho-boronic acid. X-ray crystallography and 11B NMR of this compound clearly shows that the hindered isopropylamino groups are sufficient to prevent B–N intramolecular coordination, which contrasts with N,N-dimethylbenzylamino ortho-boronic acid.

Graphical abstractDirected ortho-metallation is used to introduce a boron function into N,N-diisopropylbenzamide, resulting in the formation of both borinate and boronate derivatives. N,N-Diisopropylbenzamide ortho-boronate pinacol ester can be reduced with sodium borohydride–TMSCl resulting in N,N-diisopropylbenzylamino ortho-boronic acid; X-ray crystallography and 11B NMR shows that the hindered isopropylamino groups are sufficient to prevent B–N intramolecular coordination, which contrasts with N,N-dimethylbenzylamino ortho-boronic acid.Figure optionsDownload full-size imageDownload as PowerPoint slide