JSFiddle - React, Tailwind, and code Playground

JavaScript

var j = [{'one':1},{'two':2},{'three':3},{'four':4},{'five':5},{'one':1}];
var keyarr = [];
var unique = [];
 
j.map(function(obj, index) {
    for(var key in obj ) {
        
        if( $.inArray(key, keyarr) < 0 ) {
            keyarr.push(key);
            var newobj = {};
            newobj[key] = obj[key];
            unique.push(newobj)
        }
    }
});
console.log( unique );