[babbas]

I need some help distinguishing if the 4 species below are solvents, or catalists and if they are going to break apart and take part in the by-products of the reaction.

used in a heck reaction : n-Bu4NCl
used with a wittig reaction: KHMDS/THF
used with Cl2CH2: iBu2AlH
used with THF: (CH2)4NH3F
and finally LDA