- strtr: documentation ( source)
<?php
$a = 'ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõöøùúûýýþÿ';
$b = 'aaaaaaaceeeeiiiidnoooooouuuuybsaaaaaaaceeeeiiiidnoooooouuuyyby';
$string = 'Villa Pueyrredón';
$string = strtr($string, $a, $b);
echo $string;