Merging strain-release and copper catalysis: the selective ring-opening cross-coupling of 1,2-oxazetidines with boronic acids

An unprecedented ring-opening cross-coupling of 1,2-oxazetidines with readily available arylboronic acids is achieved for the first time by copper catalysis. Unlike the known electrophilic oxygen reactivity in coupling with organometallic reagents, 1,2-oxazetidines were utilized as formaldimine precursors in this protocol. Remarkable features of this reaction include simple operation, inexpensive catalyst, broad scope and high regioselectivity, delivering a wide array of aminomethylation products. The practicality of this reaction was validated in the one-step downstream transformation of the obtained products into synthetically important molecules and late-stage modification of bioactive acids.

Automated summary

An unprecedented ring-opening cross-coupling of 1,2-oxazetidines with arylboronic acids using copper catalysis has been achieved. This reaction offers simple operation, inexpensive catalyst, broad scope, and high regioselectivity, leading to a wide range of aminomethylation products. Furthermore, the obtained products can be further transformed and bioactive acids can be modified.