Whisk together first 4 ingredients until smooth; set aside.
Sprinkle salt and pepper evenly over chicken. Dust evenly with flour.
Melt butter in a large nonstick skillet coated with vegetable cooking spray over medium-high heat. Cook chicken 5 to 6 minutes on each side. Remove chicken from pan, and keep warm. Add pineapple juice mixture to skillet, and cook, whisking constantly, 1 minute or until thickened and bubbly. Pour over chicken.
Very nice subtle pineapple flavor to the chicken - great with a "Hawaiian" themed dinner.