var kvArray = [
            {userId: 1, id: 1,title: "sunt"},
            {userId: 1, id: 2,title: "qui"},
            {userId: 1, id: 3, title: "repell"}
          ]

var reformattedArray = kvArray.map(function(obj){
var rObj = {};
rObj[obj.userId] = obj.firts;
return rObj;
});

//   reformattedArray = [
//              {first: 1, second: 1, third: "sunt"},
//              {first: 1, second: 2, third: "qui"},
//              {first: 1, second: 3, third: "repell"}
//              ]