Is there a chemical that has the bond structure like below? (sorry, I found I could not upload the picture. So, I need to describe as below.)

There are 5 atoms linking together. Two of them have 4 bonds. (They can be either same or different atoms.) Another two of them have 3 bonds. (They can be either same or different atoms.) The last atom has only 2 bonds.

Could someone recognize what chemical it is?