How to grep connectors in a group, between two required words?

Must catch some connectors between two words in a very extensive document.

1     Joanna de Smith        

2     Felicitas de la Tour

3     Perpetua y Beatrice Kennedy

but the solution is very poor resolved in three steps and it seems should be just only one string.

1     <\u\l{2,}de ( \u\l{2,})+\>

2     <\u\l{2,} de la ( \u\l{2,})+\>

3     <\u\l{2,}y ( \u\l{2,})+\>