His boss doesn’t let him pray

Delaying the prayer until after the time when it is due, with no valid excuse, is
a major sin. Allaah says (interpretation of the meaning): 

“So woe unto those performers of Salaah (prayers) (hypocrites),

Those who delay their Salaah (prayer from their stated fixed times)”

[al-Ma’oon 107:4-5]

Sa’d ibn Abi Waqqaas was asked whether delaying prayer is counted as abandoning
prayer. He said, “No, but it means delaying it until after its time.”  

Ibn ‘Abbaas said: “ ‘Those who delay their Salaah’ means those who delay it until
after its time.” 

Tafseer al-Qurtubi, 12/706. 

Work is not a reason for not praying until the time for prayer is over. Allaah
says (interpretation of the meaning): 

“In houses (mosques) which Allaah has ordered to be raised (to be cleaned, and
to be honoured), in them His Name is remembered [i.e. Adhaan, Iqaamah, Salaah (prayers), invocations, recitation of the Qur’aan]. Therein glorify
Him (Allaah) in the mornings and in the afternoons or the evenings,

Men whom neither trade nor sale (business) diverts from the remembrance of Allaah (with heart
and tongue) nor from performing AsSalaah (Iqaamat asSalaah) nor from giving the Zakaah. They fear a Day when hearts and eyes will be overturned
(out of the horror of the torment of the Day of Resurrection)”

[al-Noor 24:36-37]

al-Sa’di said: 

These men, even though they engage in trade and buy and sell, that does not distract them from
remembering Allaah and establishing regular prayer and praying zakaah. Rather they make obedience and worship of Allaah their main aim and
ultimate goal, and whatever comes between them and that goal, they shun it. 

Based on this, you should either ask your boss to allow you enough time to pray on
time, or you should leave this job which is keeping you from prayer. And whoever gives up something for the sake of Allaah, Allaah will compensate
him with something better than that. 

See also Question no. 34617 

And Allaah knows best.