Can a person on Asylum in the US get work Visa for Canada?

Your question should be directed to a Canadian immigration attorney. From the U.S. immigration law side, my advice would be to get a green card in the U.S., first. Having a U.S. green card would also make things easier if he will have to travel internationally with the team. If your friend received asylum very recently and would lose the opportunity if he waits for his green card, he should obtain a U.S. refugee travel document and a re-entry permit before leaving the U.S.

You should direct your query to an experienced Canadian immigration attorney. Having an asylum status in United States will not necessarily diminish your eligibility for status in Canada if you are otherwise eligible for such status. However, I must point out you should consult in depth both with an experienced U.S. immigration lawyer as well. It is unwise to be a U.S. legal resident alien green card and simultaneously hold the similar status in Canada