Table 5. Screening of Reaction Conditions for the 1,1-Difluoroolefination of N-Tosylhydrazone^a.

entry	change from standard conditions	yieldb
1	none	70%
2	PC (2 mol %)	77% (73%)c
3	one-pot, PC (2 mol %)	75%d
4	without Cs2CO3	n.d.
5	without PC	n.d.
6	in the dark	n.d.

^aReaction conditions: compound 7a (0.2 mmol), 8 (0.3 mmol), Cs₂CO₃ (0.3 mmol), [Ir(dFCF₃ppy)₂dtbbpy]PF₆ (1 mol %) in 1 mL of solvent, irradiation with blue LED (455 nm) at 25 °C for 24 h. n.d. = not detected.

^bYields were determined by ¹⁹F NMR analysis of the crude reaction mixture using 4,4′-difluorobenzophenone as the internal standard.

^cIsolated yield.

^d7a was formed in one pot starting from corresponding ketone and used directly without purification. PC = photocatalyst.