https://doi.org/10.1351/goldbook.V06620
@[email protected] having a @[email protected] on a carbenic carbon atom R2C=CRC:R\(\leftrightarrow\) R2C+–CR=C−R . E.g. H2C=CHC:H prop-2-en-1-ylidene.
See:
1,3-dipolar compounds