This is what I am wondering about also.
@momshope Your son might want to talk to his academic advisor at his current school.
There is at least some research going on at and/or near a rather wide range of colleges and universities. Both daughters got either appropriate research opportunities or work experience at organizations that were not strictly speaking related in any way to the university that they attended, but that were nearby in the area and naturally knew about the university as a source of potential low cost, smart, enthusiastic, but young employees. One was with a private employer, the other was with a government sponsored research organization.
One issue at an R1 university is that they have graduate students (my understanding is that having a range of PhD offerings is part of the definition of “R1”). This means that undergraduate students need to compete with graduate students for the research opportunities. Your son as a transfer would also need to compete for research opportunities with students who have been at the same university all along and have had an extra year to get to know the professors.
I would have thought that UVA and BU would be reaches at this point, or at least far from assured for a transfer particularly if you need any financial aid. I do not know Tulane. We do have a neighbor who transferred into BU, but I do not know what his college GPA was.
I would be tempted to look for an internship for the summer anywhere near either his current school or your home. Even if the first internship is not exactly ideal, it can still make him a more attractive candidate for other future internship opportunities.