Going a bit overkill, but the following supports a large subset of the escape sequences supported by Perl (Quote and Quote like Operators). Even though it uses eval (via s///ee) it's fairly safe as it only evaluates known escape sequences.

$str =~ s{( \\ (?: [tnrfbae\\] | [xNo] \{ [-+,\w ]* \} | [0-7]{1,3}
     | x[0-9A-Fa-f]{0,2} | c[\@A-Za-z[\]^_?] ) )}{ qq{"$1"} }msxeeg;
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