captures the marked stone, which makes the first eye and threatens to make two eyes on the left side. After connects the solitary white stone, makes a second eye around a.
Although looks promising, it doesn't work. threatens to cut off the left side from the rest, so is forced. After , black can make only make one eye. White will destroy the other by playing at one of the a points.
emeraldemon: I think this also works, making a and b miai.
When White destroys the eye on the right, secures enough room for two eyes. There is no killing shape and more than enough liberties.