const temp = [{first: 569, second: "789", third: "458"}, {first: 476, second : "147", third: "369"}, {first: 100, second: "200", third: "300"}, {first: 100, second: "200", third: "300"}, {first: 100, second: "200", third: "300"}];
const result = [...new Set(temp.map(obj => JSON.stringify(obj)))]
.map(str => JSON.parse(str));
console.log(result);