A pyrrolidine-mediated Knoevenagel-type reaction for highlystereoselective construction of novel α-halo-1,3-dienylsulfonyl fluorides was achieved in up to 100% Z-selectivity and high yields at room temperature from condensation of the readily available aldehydes and halomethanesulfonyl fluorides. This protocol provided a class of unique α-halo-1,3-dienylsulfonyl fluorides with wide scope and excellent