The [3+2]-cycloaddition reaction of isoselenocyanates with oxiranes using BF3·Et2O is temperature dependent affording generally either substituted 2-imino-1,3-oxaselenolanes (−5 °C) or 1,3-oxazolidinones (40 °C) in short reaction times with high yields.
![Graphical abstract: Role of temperature in [3+2]-cycloaddition of isoselenocyanates with oxiranes using BF3·Et2O](http://hg.y866.cn/compound/lib/scimg/usr/1/C2RA00042C.jpg)
