What does the 2 in TCB-2 stand for? by the way. Is it because it's the "2 carbon" like 2C, so the corresponding amphetamine would be called TCB-3 ? That would be kind of wrong because there's actualy only 1 carbon on the amine chain as the other carbon is part of the cyclobutene ring.
Probably not, because there is not a simple and linear amine chain it is not appropriate anymore to just simply count carbon atoms and call them alpha and beta. Now it is a bicyclic molecule, the main part is the body with 2 rings and it has a mini-"chain" sticking out on the right now with only one carbon. In the main bicyclic body the total number of carbons are counted which makes 8. Then the number of carbon are counted that are between the carbons that unite the rings.
What used to be the alpha is now the 1-position.
A question I find more interesting is what the T in the name stands for. I think it is either for
Two
CB or for tertiary because the carbon on the 1-position is tertiary but that would be a pretty awkward name. After all amphetamines have that as well.
The original name was 2CB-CB. I think they turned that into 2CB-2 because 2CB-CB is seen as a 'next' member in the modded 2C-B series and changed the 2 into a T to mask the fact that the 2 has stopped making sense since it is not a 2-carbon chain. You could say: 'but isn't it a next version of DOB?', but yeah it is just as much a cyclobutene version of 2C-B as it is of DOB.
There is no corresponding amphetamine because there is no more alpha-position to justify the name amphetamine (= alpha-methyl PEA). If you add a methyl on the 1-position, AFAIK it would probably be constrained (forced) to stick out in a direction that is uncomfortable for binding.
Whether it can be called TCB-3 or not would mostly depend on whether you still find that molecule to be a modification of 2C-B rather than DOB.
IMO what you propose would be appropriately named DOB-CB
The name TCB-3 is not reserved for the cyclopentene analogue, which is called 2CB-Ind so it would be hard to continue the nomenclative series consistently.