SQL Server tail log backup fails where it shouldn't
Paul Randal did a good piece on backing up the tail of the log that includes just this case.  In it he says that the method to use when there is no data file is using NO_TRUNCATE.  Based on that your command should be: 

BACKUP LOG [AdventureWorks2012] TO
DISK = N'C:\sqldata\MSSQL11.MSSQLSERVER\MSSQL\Backup\AdventureWorks2012.bak' 
WITH NAME = N'AW Tail Log Backup', NO_TRUNCATE


BOL does say


  To perform a best-effort log backup that skips log truncation and then take the database into the RESTORING state atomically, use the NO_TRUNCATE and NORECOVERY options together. 


So you could try using both of them together but I'm not sure if NORECOVERY can be used if the data file is missing or not, even with NO_RECOVERY.  

BACKUP LOG [AdventureWorks2012] TO
DISK = N'C:\sqldata\MSSQL11.MSSQLSERVER\MSSQL\Backup\AdventureWorks2012.bak' 
WITH NAME = N'AW Tail Log Backup', NO_TRUNCATE, NORECOVERY


It's certainly worth testing anyway.