Table 1. Optimization studies ^a .

Entry	Deviation of the reaction conditions	Yield b 3a, %
1	None	91 c (75) d
2	Without NaCl (H2O)	17
3	Without NaCl	48
4	Under air	10
5	Without i-Pr2EtN	0
6	In the dark	0

^aReaction conditions: 1a (0.10 mmol), 2a (0.10 mmol), i-PrEt₂N (0.20 mmol), CH₃CN (1 mL), NaCl (1.25 M in H₂O, 0.5 mL). Reactions were degassed prior to irradiation.

^{b 1}H-NMR yields calculated using 1,2-dimethoxyethane as the internal standard.

^cYield of the isolated product adding additional 2a (0.10 mmol, 1 equiv.) and i-PrEt₂N (0.20 mmol, 2 equiv.) after 4 hours.

^dYield of the isolated product using 1 gram of (E)-1a and 1 equiv. of 2a. See the ESI for the evaluation of other solvents, amines, or visible-light sources.