Sulfinylamine
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. Sulfinyl amines are dienophile. They undergo cycloaddition to ketenes.
According to X-ray crystallography, sulfinylamines have planar C-N=S=O cores with syn geometry.