Try this one.
double angle = Math.Atan2(Chest.chests[0].minY - Move.position.Y, Chest.chests[0].minX - Move.position.X );
Enemy_Shot tempshot = new Enemy_Shot(Chest.chests[0].minX, Chest.chests[0].minY, Chest.chests[0].minY * Math.Cos(angle) * 0.1f, Chest.chests[0].minX * Math.Sin(angle) * 0.1f, Game1.bossmissile);
Enemy_Shot.shotlist.Add(tempshot);