UA/NH/AC - YYZ > SIN for $4,463 CAD in J
Found this gem whilst searching award availability on ExpertFlyer:
https://www.google.com/flights?lite=...16*.CAD.446216
Seems to be scattered availability till the end of the year but never the less a decent deal considering you'll have Polaris service in both directions, giving you access to the PL in ORD and SFO respectively.
-James