In practice or in fictional books? If in practice I’m sure you can share a handful of examples.
https://en.wikipedia.org/wiki/Fordl%C3%A2ndia
And for a really dark example:
https://en.wikipedia.org/wiki/Colonia_Dignidad
Also Disney's failed attempt:
https://en.wikipedia.org/wiki/EPCOT_(concept)
Finally an example that actually worked:
https://en.wikipedia.org/wiki/Siemensstadt
...the project reminds me much more of the Chinese 'fake European cities' though:
https://www.telegraph.co.uk/books/non-fiction/duplitecture-d...