Table 2.

Optimization and scope for flow application

Entry	Deviations from standard conditionsa	Yieldb
1	None	85%
2	DMF/ACN 3:1, 60W	78%
3	DMF, NaHSO4 (1 equiv)	traces
4	45°C	49%
5	Catalyst loading = 2.5 mol%	71%
6c	In batch under blue-lights (2 × 40W)	traces
7	Stop-flow	37%
Scope:

^aReaction conditions: solution A: 1a (0.2 mmol), 3a (0.6 mmol) and iridium photocatalyst (3.5 mol%) in DMF/ACN (2 mL). Solution B: 2a (0.3 mmol) in DMF/ACN (2 mL). Solution A and B were pumped at 0.1 mL/min.

^bThe yields were based on isolated products.

^cNo stirring.