In 2006, the detection of cyanoallene (CH₂CCHCN) toward the Taurus Molecular Cloud (TMC-1) was reported in two papers. Lovas et al. observed four lines with the 100 m telescope at Green Bank, West Virginia. Their observations found hyperfine structure in some of the observed rotational features. Chin et al. also observed four lines, two in common with the other study, using the 100 m Effelsberg telescope.

Cyanoallene and methylcyanoacetylene, another observed interstellar compound, are isomers that have the same composition, C₄H₃N.