Sulfinylamine

Sulfinylamines (formerly N-sulfinyl amines) 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.^[1] They undergo [2+2] cycloaddition to ketenes.^[2]

General structure of an N-sulfinyl amine

N-Sulfinylaniline is a common sulfinylamine

According to X-ray crystallography, sulfinylamines have planar C-N=S=O cores with syn geometry.^[3]

Preparation

Sulfinylamines can be made when thionyl chloride SOCl₂ reacts with a primary amine.^[4] Indeed, the parent thionylamide, HNSO, can be made that way at low temperature.^[5]

Reactions

A frustrated Lewis pair, such as tris(tert-butyl) phosphine and tris(pentafluorophenyl)borane, can attach to the NSO chain to yield a R'₃P=N⁺(R)SOB⁻R"₃ compound.^[4]

Compounds

Formula	Name	CAS No	PubChem CID	Chemspider ID	MW (g/mol)	Reference
HNSO	Thionylimide Sulfinylamine Sulfoximine	13817-04-4	139610	123125	63.074	[6]
C6H5NSO	N-Sulfinylaniline N-Thionylaniline	1122-83-4	70739	63904	139.172	[7]
	N-Sulfinyl-2,6-diethyl benzenamine					[7]
	N-Sulfinyl-2-aminopyrimidine	110526-12-0	14790782		141.148
	N-Sulfinyl-n-butylamine					[8]
	N-Sulfinyl-n-pentylamine					[8]