GPhos Ligand Enables Production of Chiral N-Arylamines in a Telescoped Transaminase-Buchwald-Hartwig Amination Cascade in the Presence of Excess Amine Donor

The combination of biocatalysis and chemocatalysis can be more powerful than either technique alone. However, combining the two is challenging due to typically very different reaction conditions. Herein, chiral N-aryl amines, key features of many active pharmaceutical ingredients, are accessed in excellent enantioselectivity (typically>99.5 % ee) by combining transaminases with the Buchwald-Hartwig amination. By employing a bi-phasic buffer-toluene system as well as the ligand GPhos, the telescoped cascade proceeded with up to 89 % overall conversion in the presence of excess alanine. No coupling to alanine was observed.

Automated summary

The combination of biocatalysis and chemocatalysis can provide a powerful method for accessing chiral N-aryl amines in excellent enantioselectivity. The use of a bi-phasic buffer-toluene system and the ligand GPhos allows for a telescoped cascade with up to 89% overall conversion in the presence of excess alanine, without observed coupling to alanine.