Try additional quotes around the variables - two single quote for escape

EXEC('

INSERT INTO dbo.ImportError

(DataElementID, CenterCode, ValueType, ValueDate, [Value], ImportDate, BatchID, ErrorReason)

SELECT

DataElementID, CenterCode, ValueType, ValueDate, [Value], GetDate(), ''' + @BatchID + ''', ''' + @ErrorReason + '''

FROM dbo.ImportAccess

WHERE' + @WhereStatement)