Researchers from the National University of Singapore (NUS) have developed a boron-catalyzed method to transform oxetanes, which are small four-membered ring molecules, into larger, medicinally relevant 1,3-oxazinanes by the selective insertion of two building blocks, a carbon unit and a nitrogen unit. The research team was led by Associate Professor Koh Ming Joo from the NUS Department of Chemistry. The research breakthrough was published in the journal Nature Synthesis on March 12, 2026.