You can fly Single Pilot Aircraft in EASA , if EASA recognizes these as such, and they are labelled High Performance Aircraft. Usually the rating comes in two versions SPO and MPO.
The aircrafts listed above can be flown single pilot in Europe, since they are ticking the box of both regulations. A C560 (Citation 5) is not eligible in EASA for Single Pilot operations since this rating in EASA is only multi-pilot.
14 CFR requires ( like all regulations) to comply with countries overflown regs ( age limit, etc..) as a consequence, coming S/P across the pond in a C560 is not possible.
I will see some jumping, saying that the main base is in connecticut, and blablabla... If you operate from Europe on a daily basis, you aircraft is hangared at the same place, not only you will need a **** load of LOA's put also a part NCC authorization ( which includes a MEL, LOA 095 is not enough, except on some grandfather's rights for some operators, the other one's will need LOA 195)...