Question

Why is carbene an electrophile?

Answer 1

Around the carbon in dichlorocarbene there 6 electrons; it would "like" to have 8.

Explanation:

The carbon in methane has 6 electrons. Two are inner shell and do not participate in bonding. Each hydrogen atom contributes 1 electron, and the carbon has 8 electrons to form 4 covalent bonds.

Now consider carbene, or dichlorocarbene, `Cl_2C:`. With the electrons from each `Cl-C` bond, carbon has a total of six electrons. It thus will react with electron rich species, with olefins, to go from sextet to octet.

Note that in all of these examples the carbon remains neutral.