Abstract 3, 5-Bis (trifluoromethyl) phenyl (BTFP) sulfones 8a–d are successfully employed in the modified Julia olefination reaction with carbonyl compounds employing phosphazene base P4-tBu at room temp. in THF, affording tri-and tetrasubstituted olefins in good yields. The Julia–Kocienski olefination between primary alkyl BTFP sulfones 8a, b and aromatic and aliphatic ketones affords the corresponding trisubstituted alkenes in good yields and ...