Catalytic N-Acylation for Access to N–N Atropisomeric N-Aminoindoles: Choice of Acylation Reagents and Mechanistic Insights
Chaoyang Song, Pang Chen, Youlin Deng, Hui Cai, Xiuhai Gan, Yonggui Robin
Abstract
The synthesis of N–N axial compounds containing aromatic acyl amides using common acylation reagents remains challenging. We describe a highly atropenantioselective synthesis of N-aminoindoles containing N–N axes. A chiral cyclic isothiourea is used as the sole organic catalyst in the atropenantioselective transformation of the N-acylation reaction. Aroyl chlorides have been used as acylation reagents to construct atropisomeric compounds through N-acylation. The N-aminoindole products, which bear stereogenic N–N axes, were synthesized with high yields and enantioselectivities. Some of the enantiopure N-aminoindole products exhibited promising antibacterial activities against plant pathogens.