Entity Framework Update without reading

Is there a way to update a single table / entity without having to read the entity first into a list. This is the sql I am trying to achieve.

Update table set col1 = Case col2 When 0 then 1 else 0 end this updates roughly 500,000 records under a second

I do not want to do

 List<table> updRecs = Context.tables.toList();
 for each
 {
  if(col1 == 0)
  col2 = true 
  else
  col2 = false
 }

Context.SaveChanges();

above is very slow roughly 4 minutes.