boranylidenes

https://doi.org/10.1351/goldbook.B00710
The species RB: containing an electrically neutral univalent boron atom with two formally non-bonding electrons.
See:
carbene analogues
Source:
PAC, 1995, 67, 1307. (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1323 [Terms] [Paper]