Using dynamic variables in $.when

How to use dynamic deferred's inside $.when? Got one function ajaxFunction which returns deferred promise.

function ajaxFunction(image){
    var dfd = $.Deferred();
    //Ajax of image
    return dfd.promise();
}

calling this ajaxFunction based on dynamic condition like

var defs = {};
var someQuerySelector = document.querySelectorAll('image');
for (var i = 0; i < someQuerySelector.length; i++) {
    defs[d + 'i'] = ajaxFunction(someQuerySelector[i]);
}

Now I want to use these into $.when() how to use defs dynamic keys inside like $.when(defs['d1'],defs['d2']). How to use dynamic variables into this. Any change in approach or help will be highly appreciated.