<?php
/*
    Usage:
    domain.com/plugins > domain.com/wp-admin/plugins.php (WP Admin > Plugins)
    domain.com/pg > domain.com/wp-admin/edit.php?post_type=page (WP Admin > Pages)
    etc...
*/ 
add_action('wp', 'redirect_shortcuts');
function redirect_shortcuts(){
    if (is_user_logged_in()) {
        global $wp;
        $url = '';
        switch ($wp->request) {
            case 'pl':
                $url = admin_url('plugins.php');
                break;
            case 'plugins':
                $url = admin_url('plugins.php');
                break;
            case 'pg':
                $url = admin_url('edit.php?post_type=page');
                break;
            case 'pages':
                $url = admin_url('edit.php?post_type=page');
                break;
            case 'media':
                $url = admin_url('upload.php');
                break;
            case 'jch':
                $url = admin_url('options-general.php?page=jchoptimize-settings');
                break;
            default:
                break;
        }
        if ($url) {
            wp_safe_redirect($url);
        }
        return;
    }
}