Sulfinylamines are organosulfur compounds with the formula RNSO where R = an organic substituent. These compounds are, formally speaking, derivatives of HN=S=O, i.e. analogues of sulfur dioxide and of sulfur diimide. A common example is N-sulfinylaniline. The S-N bond in sulfinylamines is a dienophile. They undergo [2+2] cycloaddition to ketenes.