Ultrasound promoted environmentally benign, highly efficient, and chemoselective N-tert-butyloxycarbonylation of amines by reusable sulfated polyborate

The sulfated polyborate catalyzed an efficient and chemoselective N-tert-butyloxycarbonylation of amines under ultrasonic irradiation is developed. A broad substrate scope has been demonstrated for N-Boc protection of various primary/secondary amines. It allows converting several aliphatic/aryl/heteroaryl amines, amino alcohol, aminoester, and chiral amines to their N-Boc-protected derivatives under solvent-free conditions with excellent yields. The protocol has several advantages such as easy catalyst, and product isolation, short reaction time, excellent yields, outstanding chemoselectivity, and catalyst recyclability, among others. This makes the process practicable, economical, and environmentally benign.

Automated summary

The developed reaction of amine N-tert-butyloxycarbonylation using sulfated polyborate under ultrasonic irradiation is demonstrated to have a broad substrate scope and excellent yields. The protocol offers advantages such as easy catalyst and product isolation, short reaction time, high selectivity, and recyclability, making it a practical, economical, and environmentally friendly process.