curl -X PUT https://api.box.com/2.0/folders/4353455 \
     -H 'Authorization: Bearer <ACCESS_TOKEN>'
     -H 'Content-Type: application/json" '
     -d '{
       "name": "New folder name"
     }'

client.folders.update('12345', {name: 'New Name'}, callback);

Name restrictions

There are some restrictions to the file name. Names containing non-printable ASCII characters, forward and backward slashes (/, \), as well as names with trailing spaces are prohibited.

Additionally, the names . and .. are reserved names and therefore also prohibited.