Why that particular corner creates the ambush
The problem is architectural before it is behavioural. At a blind turn, the cat rounds the corner and meets a dog at point-blank range with no time to assess or retreat, and the dog, who may have heard paws approaching, gets a sudden close-range appearance that triggers chase before thought. Even a dog who is relaxed about the cat in open rooms can ambush at this spot, because the surprise does the work. The cat learns the turn is dangerous and starts sprinting past it pre-emptively, which makes her even more chase-worthy, and the hallway becomes a daily flashpoint. Scolding the dog after a chase does not change the geometry that caused it. Redesign the crossing first, then train calm behaviour into the new setup.
Change what each animal can see and do at the turn
Put something at the corner that breaks the ambush without trapping the cat: a baby gate the cat can jump or slip under but the dog cannot pass, a piece of furniture angled to slow the dog's approach, or a door kept positioned so sightlines open earlier. Give the cat a superior route past the turn, such as a shelf, a cat tree or a clear run along a wall, because a cat who can pass above or around the danger zone stops needing to sprint through it. Make sure the cat is never cornered at that turn with the dog between her and escape; ambushes turn serious when the fleeing animal runs out of exits. If greetings must happen in the hallway, let them happen on the straight stretch where both animals can see each other approaching from a distance.
Train the dog's job at the crossing point
With the layout safer, teach the dog a specific behaviour for that location: a station on a mat set back from the corner, or a recall away from the turn to you, paid generously. Practise initially without the cat, until going to the mat when he reaches the hallway is automatic, then add the cat at a distance with the dog on a lead or behind the gate, rewarding every look at the cat followed by disengagement. Short, successful repetitions matter more than testing him free at the crossing. If he fixates, cannot take treats or has already caught and injured the cat, keep them separated at that crossing permanently and seek a qualified behaviour professional, because predatory behaviour toward a household cat is a safety issue, not a manners project.
Protect the cat's confidence across the whole home
A cat who is ambushed in the hallway often starts avoiding whole areas, hiding more, or toileting away from a litter tray she must cross the danger zone to reach. Watch for those wider signs and, if you see them, increase her safe territory with trays, food and resting places on her side of the house while training proceeds. Let the cat set the pace of any shared time; a cat who chooses to be near the dog in an open room, with exits available, is showing you trust is rebuilding. Do not carry the cat to the dog to prove they can be friends, and do not force meetings at the turn to test progress. Mention any injuries, however small, to your veterinarian, since cat and dog altercations can leave punctures that are easy to miss under fur.
Get the whole household running the same layout
The gate left open by one person or the mat moved during cleaning quietly restores the ambush, so the physical plan and the training steps need to be shared knowledge, not one person's system. Walk everyone through where the gate stays, where the cat's high route runs and what to do when the dog heads for the corner. Family members selected by you can be granted profile access for the cat and the dog in KinsLe Family Sharing.