查询laravel中的regexp雄辩

I'm using laravel 5 And I want to run this query

SELECT *
                FROM `discussions`
                WHERE
                  `title` REGEXP CONCAT('[[:<:]]', REPLACE('".$term."', ' ', '[[:>:]].*[[:<:]]'), '[[:>:]]')

I tried this

Discussion::where('title', 'REGEXP', "CONCAT('[[:<:]]', REPLACE('".$term."', ' ', '[[:>:]].*[[:<:]]'), '[[:>:]]')")->get();

But I did not get back anything (not even an error) Can this be done?