If you need to escape characters in a regular expression, you can reliably use either the quotemeta function or the delimiters \Q and \E, as described in Quote and Quote like Operators. For example, you would successfully split with
my @arr = split /\Q),(\E/, $str;.
in reply to split on the pattern of '),('
On examining your input, it's possible you'll get more mileage from either a state machine character-wise parser, a regular expression, or my favorite in this context, multiple operations including a different basic split. Since you appear to be separating tuples, you could use
my @arr = split /(?<=\))\s*,\s*(?=\()/, $str; to separate the tuples, and then deal with each one individually.
#11929 First ask yourself `How would I do this without a computer?' Then have the computer do it the same way.