How to escape single curly braces angular 4 template

You can use Special Character for { --> { and for } --> }

<div>
  yada yada.... &#123; ... &#125;  blah blah....
<div>

<div>
  yada yada.... {{ '{' }} ... {{ '}' }}  blah blah....
<div>

there is a open bug for ngNonBindable

You can bind the text to a string literal:

<div>
  {{"yada yada.... { ... }  blah blah...."}}
<div>

(if the text also has quote marks in it, you can escape them with \)

Edit: just saw your comment that you need to keep ngNonBindable. It looks like there's an open issue for that, so until that's fixed you may need to see if you can restructure your markup to remove the escaped text from the ngNonBindable section.